O.k. I can imagine the comments that are going to get this thread deleted already but here goes.
Mine is fixing cars. I used to have to fix my car out in the open because of my living situation and I couldn't hide it. Now I can fix it behind the house and nobody can see, 4 cars 4 drivers in my family, one mechanic.
I also sometimes hide the fact that I know how to write grant solicitations. I don't get as much exposure with that.
How about you?