It's over if you decide it's over. I've known people in their late 20's who have given up on all that already. And I've known folks well into their 70's who are happily married/dating, traveling, doing hobbies, healthy, etc.
If you give up on life, then of course you won't get anything out of it. I hate how people act like getting older just means you become boring, weak, ugly, broken down, slow, etc.
If your life is over when you turn 50, it's because you chose to let it be over.