Not sticking up for myself.
Don't wait for some theoretical FU money.
The people who have FU money, if they didn't inherit it, seem to have incorporated my first point into their lives. (Not that money is necessarily the outcome.) Also, sticking up for yourself does not equal being an ass to other people. For myself, treating other people nicely/respectfully is inherent to my own well being. And I actually do worse at it when I am not taking care of myself.
As for the "I should never have made the mistake" aspect. My intellect, and/or my intuition, could read the situation. But lack of will power, conditioning, health, or whatever -- something held me in place.