I have no kids and I feel very weird about my age. I am about to turn 40 and feel 30 and 60 at the same time. I think of myself as 30, but really feel like 60. I have little energy left after a day at work or even on the weekends. I cannot consistently put energy behind any effort. I used to hack on my side projects before and after work. Now it's a great success if I do it 2-3 hours/month. I feel my mental state declining and worry that I won't be able to get another job ever again. When I say "mental state" I mean capability, energy and maybe even sanity. I think too much about unknowable things like sentients, nature of reality, purpose of life and sometimes wonder if reality is real and it demotivates me. Life feels on rails, like a movie playing in front of me, more than anything I can interact with. I feel like a passenger. Maybe it's just a result of depression and not old age.