[JohnBooty]

Anecdotal: I've found that personality is a choice, to an extent.

If you've ever known somebody who served in the military, you know that they often come back a changed person. I'm not talking about PTSD in combat vets, I'm just talking about simple personality traits like neatness.

On a more self-driven note, I became a less patient person in some specific ways after I lost a parent some years ago. (Because it become painfully obvious how limited our time is...)