What If ...

Alternate history is a fascinating genre. The further back in history you go, the more a little change can change all kinds of things. This is known as the "butterfly effect" whereby something as little as the death of a butterfly might start a chain of events that would totally alter the course of the world.
There is an old proverb that goes like this:

For want of a nail the shoe was lost.
For want of a shoe the horse was lost.
For want of a horse the rider was lost.
For want of a rider the battle was lost.
For want of a battle the kingdom was lost.
And all for the want of a horseshoe nail.

--Wikipedia article

The concept is the germ for all sorts of speculation. And thus, some very interesting fiction. In such fiction, real people in real situations are used. When things change, then new people may, and most likely do, come into existence.

A lot of alternate history is "wishful thinking" on the author's part, but if done right this avenue can be used for great philosophical musings. The old film "It's a Wonderful Life," starring Jimmy Stewart, was a fanciful look at a world minus just one man. A couple of theological titles have queried the idea "If Jesus had not come," though the one I read did not do the idea justice.

Along side the "alternate history" genre comes the "time travel" device that comes to the rescue in some science fiction (most notably the Star Trek franchise). In such cases, the theory of quantum physics leaves room for countless "alternate realities" to exist along side each other. The sci-fi favorite "Sliders" played on this theory.

Anyway, that is what I am "into" these days. Maybe a book will come of it someday -- but only after two or three OTHER books are written (some of which are half-way done now!).