Imagination
A very close friend of mine and I made a Promise to ourselves when were in our early teens. We promised to always 'think' young even if our bodies would eventually not let us 'act' young. Over the years we have 'checked in' with each other and I am glad to report that: Yes we are still 'thinking young'!

To this end I have always done things that will feed and stimulate my imagination.

One the of things I do that helps me to 'keep thinking young' is my hobby of gaming. Not video or computer gaming, but board gaming. The kind of games that are played by 2 or more people that demand your full attention, direct competition, (or cooperation) and social skills. They are played with card stock or plastic pieces, on a marked board or gridded map with rules, dice, pencils and paper.

I currently own a collection of about 250+ games. Since one of my passions is history, a fair number of these games are historical in nature. They are simulations of battles in history. You may be thinking of Risk or chess, but these games are far more involved than either of those. (both of which I own and enjoy - but I'm terrible at chess).

Imagine being Alexander, Rommel, Napoleon or Grant. I use my imagination to re-create these events on my dining room table-top. I explore what-Ifs and share a lot of fun with good friends.

In the future I will put up a list of each of the games I have. And yes I'm always looking for more games to add to my collection.