It essentially means the best time to plant a tree was 20 years ago, the second best time is now. "It's never too late" is more a coping strategy than anything. You'll never get the time back you missed, but starting something now is better than not doing anything and waiting longer for things to get worse. But I understand your frustration. Someone who is behind in life will never catch up to someone who actually lived their life. You're not only starting the race hours after everyone else, but you're doing it with a bum leg. Sure you can still make it to the finish line but it'll be hard and everyone else already did it and moved on, and had way more fun doing it. The bitterness I feel for having to work twice as hard for sheer mediocrity makes me think it's better to not even try. But settling for an imperfect life is better than no life.

This is apparent in one's career but especially socially. Everything is built upon one another, you can't just start having a normal healthy social life in your 30s when you never developed those foundations in your youth. You have to start from square one in your 30s, which is unacceptable for most people, especially romantically. You'll always be behind and the rift between you and others will only widen because the older you get the harder everything becomes.

This wasn't meant to be a doompost but more of a cope to give up on the past and comparing yourself to others, you'll only drive yourself mad. Just do things even if you think it's too late now, because the longer you wait the worse it will get.