As a writer, that mantra has been repeated over and over again: Write what you know.

Of course, if that were really true, there would be no Science Fiction or Fantasy. So what they really mean by that would be: write your characters based on your own experiences.

So for my own characters, at some point in the story they might be:

homeless
struggling
introverted
smart
but not perfecgt (SIC), (Heh, funny that I wrote it like that the first time, then decided not to correct it, since it fit in.),
wandering with no real focus on what they should be doing
naive
but not completely hopeless
trusting
reaching for something, but not knowing what (Goes back to wandering I know)
adept at something they don't like to do, but have to do it to pay the bills
knowing that there's something beyond this life than heaven and hell or purgatory


All of which I have experienced in my lifetime.

In the current Simmons Chronicles series, I've managed to put most of that into several different characters, as well as some life experiences. I hope it makes the characters believable.

As the second part of that series comes to life I'll be adding to that. That book will show a definite decline for a couple of the characters (I won't say which), but since I tentatively titled it 'Darkness' that should be considered a clue. It begins light, then one character falls into darkness, followed - literally by another who is searching for that person as well as searching for him/herself, then both come rising just as things get really dark. The story ends very dark, yet not without hope.

The story of my life.