I've heard it said that youth is characterized by energy and drive, and age by structure and stability. I believe there's a lot of truth to this. All living systems need both energy and structure. If you have structure without energy, action or change is impossible. If you have energy without structure, the result is chaos. If you're my age, hopefully you have abundant energy and a well-developed structure. If you don't, no need to despair. There's still time to gain drive and stability. After all, you'll need both if you want to function at your maximal level. In time, of course, both will decline and dissolve. But until then, embrace your age and continue to develop as a person. Despite the challenges, the only reasonable choice is to get on with the work!