By far my favorite. IMDB list that his character is based on the English philosopher, not that IMDB hasn't made mistakes before.
His only friends before he left for Aus. were the ones he played Role playing games with. He also had an attachment to a phone sex operator named Helen, he used her more like a psychologist from the gist of the one conversation we heard, he passed her off at work as his girlfriend. Yes, he worked in a box company, his explanation in "Hearts and Minds", as a collections agent. I would guess it is the same box company Hurley now owns, I think I remember one of Locke's bosses saying something about new ownership.
He has an extensive knowledge on survival tactics bcuz he was going to Aus. for a "Walkabout", thus the name of the first Lockecenteric episode. He planned to live off the land for a few months like Crocodile Dundee, this would also explain all the different knives.
I believe before the Island he was socially inept, possibly married, then divorced or widowed, no kids, rough childhood, no military experience, coverts ops or otherwise. Since the island was his new start at life he wants to pass that opportunity on to others i.e. Charlie's heroin addiction, Boones problems with Shannon, Kate in general. I DO NOT THINK HE IS TRYING TO BUILD A FOLLOWING OR A CULT. He is just happy to feel needed and useful.
I will be adding more as his history becomes more detailed.
"When the going gets weird, the weird turn pro." Dr. Hunter S. Thompson
And please, call me Funt