Colin O'Brien is a normal guy.
I say this because that is what he says he is, or at least what he was at the time the trouble started. He says he was "a normal guy having a normal day at a normal Starbucks, enjoying a normal cup of coffee". That's when a woman in her late 30s or so approaches him and asks for a meeting. When he declines, she asks how much he would charge for one and, humoring her, he quoted $10k. She handed it to him. That got his attention. So he goes to the meeting and finds he has been mistaken for a highly dangerous and successful assassin and he is offered $1m to kill someone. Again using his own words, "Being offered $1,000,000 to kill a man can really skew your prerogatives in life".
Things get interesting from that point.
When I pointed out that O'Brien was a normal guy, I was not exaggerating. He is delightfully pretty ordinary in that he has a pretty normal life, complete with a wife named Kathy that he loves a great deal and whom he respects just as much. He is smart enough to know his place in the hierarchy of the marriage when he admits, "as bit and tough as I like to think I am, she is really the boss ... and I, quite frankly, am a moron".
To prove that last part of the observation, O'Brien decides, when he gets a follow-up call to that "job offer", heads to the requested meeting without thinking to tell Kathy. Well, he thought about it and then decided to leave her a nice cooked meal and a bottle of wine as an apology.
He really should have told her. And not taken the money in the first place. But then we would not have had the fun that followed!