I've sen quite a few quotes around that very point, similar to "You'll get the teacher you need when you need them" or
"You'll read it again and understand it on a whole different level" or
"The people in your life are there because you need them now. Don't mourn the loss of an acquaintance, it's because you don't need their lesson anymore"
I begin to think that if you don't understand the advice, you simply don't need it _yet_.