Did you know that the brain is an unbelievably elastic organ? It can change so much with minimal alterations of outside influences, changing someone's whole personality at any time. You don't have to be Phineas Gage (the guy who survived an iron bar going through his skull) for your brain to be irrevocably changed.
It's kind of reassuring that your brain can change because then you're not stuck being exactly who you were five years ago. If you take care of and stimulate your mind with exciting challenges and ideas, you're far less likely to get stuck in your ways. One way to stretch your mind is to read regularly, and what better way to read when you're on the train or settling down for a good night's sleep than with some hilarious memes! These memes are smarter than the average image macro so that they won't kill your brain cells.