I know what it's like to be a child, fitting in with my parents' beliefs and prohibitions, largely innocent of adulthood and its horrors and liabilities, free to enjoy my childhood games and obsessions without having to think about bills or mortgages or roof repairs.
I've met the challenges of middle age, when you're constantly exhausted by the demands of full-time work, household maintenance, looking after elderly parents, and maybe raising several children. You're rushing from one task to another with little time to explore your own needs and desires.
And now I'm in the throes of old age, adjusting to all the minor dysfunctions of my ancient body, hoping I'll have enough money for however long I'm alive, hoping I won't develop dementia and become a useless vegetable (but also knowing the joys of retirement and not being in thrall to some vicious boss).
In particular, it's great being able to look back at my entire life, knowing exactly what happened to me and what I did with whatever opportunities arose. I know my life has been a success and not some string of disasters and miscalculations. When I was living on my own in the 1970s, I was rather pessimistic about the future, and had no idea things would work out so well.
The once unknown future has revealed itself.