Someone just asked me whether neurons divide and multiply as do other cells in the body. My information is that they do not. In fact, an article in the New York Times several years ago reported on a study wherein scientists succeeded (for the first time) in recording individual brain cells in the act of summoning a spontaneous memory. This study showed not only where a remembered experience was registered in the brain but also, in part, how the brain was able to recreate it. This provided some direct biological evidence related to recall, much of which has heretofore been almost entirely theoretical. When a distant memory comes to mind, at least some of the neurons that fire are the same ones that fired back when the event actually happened. In some cases, researchers have been able to identify specific memories in the participants a second or two before the individuals themselves became aware of / reported having them. Take good care of your neurons! They are going to be with you for an entire lifetime—hopefully!