When you reach the old age you realize all those things you should have done when you were young. (*) When (*) the old age (*) realize (*) done
This is a companion discussion topic for the original entry at https://english.best/questions/24234,uwhenu-you-reach-uthe-old-ageu-you-urealizeu-all-those-things-you-should-have-udoneu-when-you-were-young/