Contemplation on First Person Point of View

An Amazon writer/reader forum was a question about first person point of view and seeking comment on the beginning of the poster's story. It prompted me to look at my own works in which I've used first person, but in different ways. I'll list them here and if you want to find them on Amazon and do a look inside you'll see what I mean. I took a class once at KU from James Gunn, the classic sci-fi writer who said that first person POV was the most difficult to do, but when done well, the most powerful.

3 Very Quirky Tales: 2nd story called It Was Me (I) is normal first person

Blue Kansas Sky, snooker short story: normal first person

Crazy About You, novel: first person but with a twist. At times the narrator takes a step forward in time and looks back and able to use his gained wisdom to contemplate the story.

Downswing, golf short story: first person (is this and the snooker short story the narrowest of fiction genres?)

One More Victim, novella: first person from three different years. This is my most downloaded work. Has Holocaust element.

The Saltness of Time, novella: This is an interesting one, rather a steal from Joseph Conrad. The real first person point of view is a listener, but of course the narrator is also in first person as he tells his story to the listener.

Then and Now, novel: First person but with a twist. The writer addresses the reader and then writes a different character's section in third person and then again addresses the reader in the first person as the author commenting on what he has written. I always thought it set up an interesting tension with a hell of a payoff at the end. I cry every time I reread that damn book.