Perhaps the worst advice I ever got was, not surprisingly, from my father. Upon hearing my career choice of technical writing, he sniffed confidently that there was no such profession and that I would end up starving to death. He based this assertion on the fact that in his minuscule subset of the world, there were no technical writers. What with him knowing everything, this observation must hold true everywhere. Today, everything and everyone in my life flows from my having ignored this advice.
Similarly moronic advice came from my older brother. When during college I bought a computer for word processing, he told anyone who would listen that I was sinfully wasting money. You'd think I was snorting coke off hookers' chests. "Use a pencil," he snarled, thrusting a pencil in my face. Presumably he meant for writing, not for the hookers.
The familial mental handicap didn't stop there. My mother would yell at me any time my genitals came with six feet of the color TV. The radiation would sterilize me, she said. Today, although I am quite nearsighted, I am not sterile. So I wear glasses while I contemplate a vasectomy.
My Polish immigrant grandmother takes the prize, though, for sheer jaw-droppingnessity. Visiting our local pool, she yelled at me to get out of the water. Since I don't speak Polish, it took me a while to understand all the fussing, but with my dad's help I came to realize that she was concerned about my swimming with black children. Why? (Wait for it... wait for it...) Because the black would come off their skin and get on my own.
I defy you to beat that for sheer idiocy. What's the worst advice a family member ever gave you?