Many of us feel invincible when we are young, believing we can control the aging process so that we’ll always stay forever young, as Bob Dylan once sang. But there’s a moment when everyone realizes aging is an inevitable process and that, eventually, we will have to deal with a slow decline in our physical and, quite possibly, mental capabilities. This realization and understanding that we won’t be here forever can profoundly change one’s perspective on life. Even though aging is inevitable, studies show how we think about the process can significantly impact our longevity. People with a positive view of aging live an average of 7.5 years longer than those without.Things happen as we age that are impossible to describe to younger people. However, a group of Redditors did an excellent job of explaining the truths about aging that they were not “prepared” for in a recent thread that made a lot of people feel seen. A user named sofiagympixie asked the AskReddit forum, “What’s a truth about aging that no one prepared you for?” and it received over 2,700 responses.A big takeaway is that many people feel like they stop mentally aging at a certain point, usually in their late 20s. Still, the continued physical aging they experience makes them feel like they cannot relate to the person in the mirror.Here are 17 of the most profound responses to the question: What’s a truth about aging that no one prepared you for?1. There is an end"You start to realize the older you get that the end is closer than the beginning and you still feel like you have so much more to do.""That moment where you start to get a sense that there is an end."2. It takes energy to keep everything afloat"No one prepared me for how much energy and time it takes to maintain everything—like health, relationships, and just staying organized. It’s way more work than I expected!"3. Mind/body detachment"How your mind stays young while your body starts to slow down. You still feel like the same person you’ve always been, but suddenly you notice little things changing.""This was such a surprise to me. I really expected to feel psychologically older as I aged. But physically, oh my body has betrayed me... Eyes... hair (gray, but at least I still have it)... back... knees... hips... prostate."4. The past feels closer than it is"When you get a flashback of a good memory and you realize that was over 10 years ago.""When I told my daughter about something I did 24 years ago, I had to pause for a moment."Time flies isn't just a saying. Psychologists agree that our minds lump time together based on novel experiences. When we are older, the days are a lot more similar than when we were young children. That's why when you're 80, time moves a lot faster than it did when you were 8. 5. Stuck in the wrong time"I’m 61, and sometimes I feel like this world is not for me anymore. I feel almost like an imposter. For example, I can’t find clothes I like that fit correctly, TV is abhorrent, only old music sounds pleasant, shoes are uncomfortable, I don’t recognize most celebrities or famous people in the news or tabloids, and I don’t understand the need for most new and supposedly exciting products. I’m an educated person, I still work and have an active life. I’m not a recluse. But a little at a time, I feel the world is moving on without me. I finally understand why, in her final years, my mother only watched movies from the 1950s and reminisced about the past more than she talked about the present. Her world was long gone."6. You lose friends"If you choose not to have kids, you may end up losing your friends. I turn 40 this year, and my partner and I don't see many folks these days. Parents like to hang out with other parents. And I don't have a grudge, I totally see the value for playdates, etc. But it can be a little lonely.""To be fair, I have 2 kids and lost a lot of friends because we simply don’t have the time/energy to connect regularly enough to maintain a healthy friendship. It instead falls into an awkward acquaintance stage where enough time passes between communication, and you’re not sure if reaching out to connect comes across weird."7. Your parents are aging, too"It's not just you who is getting old. Your parents are getting even older.""I feel this. Lost my mom 2 weeks before my 21st birthday. 40 now with 2 kids. I get angry/sad at a lot of milestones like my wedding and kids' stuff ‘cause my mom was robbed of them, and I was robbed of her."8. Time wasted caring about other people's opinions"It’s so freeing when that old twinge of 'why don’t they like me' pops up, and then I remember that I can not be bothered by that anymore, and magically, I don’t care!""Just wasting time in general. No thanks. I want to do as many things as possible!"9. Your friends die"Your friends start to die. It's something I never thought about."10. Time flies"Man. I don’t even feel like the days are long anymore. I just keep blinking and the weeks go by.""Yup, wake up, eat breakfast, do a couple things. Wait, it’s lunch already? Eat lunch, do a couple more things, time to prep dinner. Eat dinner, clean up, fix a few things, it’s 9 pm. I guess it’s almost time to get ready for bed? This times 10,000 for me."11. The monotony sets in"You will realize that you hate planning meals and making food every single day. It's boring, and it's too easy to fall into monotony. But you have to make lunch again and then plan for dinner again then make dinner again and what do you want to eat tomorrow so you plan for breakfast tomorrow and get up and make breakfast again and then plan for lunch again...."12. You become invisible to much of society"I wondered what felt off the last year. Gen Z is everywhere now, and I'm still asking myself when that happened."13. Adults aren't real"When you're a kid, you can't wait to 'grow up,' and then you do, and you're still you, just older. That voice inside your head doesn't change, but what you see in the mirror does. Only now you're just older and saddled with bills and stress and all of life's 'surprises.' On top of this, everyone is winging it. Absolutely everyone. Because the idea of order and a civilized society is an illusion. We're all playing by made up rules and making imaginary money and all the rest of it. A one-dollar bill costs just as much to print as a hundred-dollar bill."14. Priorities change"Things that seemed so important when you were younger, really are not important."15. Younger people's reverence"I'm middle-aged, and a funny thing is how younger people get self-conscious or apologize when there is no need. For example, they will apologize for swearing around me or mentioning something like (gasp) drinking, or drugs, or sleeping around. I think it's funny. Why would being on earth longer make me easier to scandalize? I've seen and done things that would shock them, lol, but to them I'm a very proper-looking classy older lady."16. Ageism"Doors start closing once you reach a certain age.""Ageism is real. I just turned 50 and am in a young person's career (software development). I feel how hiring managers look at me when asked to turn my camera on, during an interview that was going very well and suddenly it's 'we'll get back to you.'"17. It all catches up"Things like drinking, eating unhealthily, smoking, spending ... they will catch up. When you're young you think you're different, or you think that when it does catch up you'll be old so who cares, I won't care when I'm old anyway. You will care, though. You'll still be you. Those things won't seem like an issue right up to the moment they are. And then it's too late to take them back."This article originally appeared in September.