A lot of people think they have life figured out -- that they know exactly what's in store for them and just the path through the choppy seas of existence.

And then, for better or worse, we learn that we were wrong. About pretty much everything. And, hopefully, learn from our mistakes. We become wiser and -- with time -- we improve. Or maybe we don't.

Either way, you only get one life and these people chose to look back and share some of their biggest regrets -- offering us up some potential wisdom you can lean on to make sure you don't make the same mistakes.