The most important thing to take from this infographic is that there are ways that you can maintain a healthy brain. The ways to do this are pretty simple and self-explanitory: Eat right, exercise (your mind and your body), get plenty of rest, and find ways to release stress.
Some interesting factoids you may not have known: The brain produces twice the amount of neurons it needs during childhood. By age 6, grey matter is almost fully developed.
Feeling like you can't remember anything as you get older? There is scientific backing for that. Your brain may begin to degenerate as early as puberty. It peaks at around age 22 and only lasts to about 27. It's all downhill from there.
By the time your are 65, you will have lost about 10% of your brain cells, but hopefully you won't care by then.