I've spent half the last couple days convinced that my personality and skillset are not particularly appropriate to my stage in life. From about 30 to 60 years old I was pretty successful at life as I recall; not so much so from 12 to 18, but I remember ages 7 to 11 fondly.
All this semi-quantitative life evaluation depends utterly on the vagaries of memory. It occurs to me that back in about 1983 I was recalling the success I had in a series of college classes. When I checked my memory against the grade reports I found that there was a rather poor correlation. The classes I remembered as being most successfully completed were not the ones with the highest grades, generally speaking.
Now it could be that the courses I remembered most positively were successful experiences according to some metric other than grades. I might have learned more or enjoyed the experience more or found more ways to apply the content to my subsequent life experiences. Reevaluating past experiences in terms of later ones is reasonable and helpful.
Categorizing the totality of life as being well or poorly matched to the sum of the challenges and relationships among which I live is probably not as useful. Cross-comparisons with other stages of life are almost certainly misleading, and reducing the sum of all that I am experiencing to a category delimited by age alone is a fundamental error in logic.
In actual reality life is more complex than such a simple model can capture. True enough, but I'm not sure how useful that insight is for an old guy in 2019.
Or how well that old guy is listening to his own wisdom.