I was playing Scrabble against my PC today, and it played the word milty. "Milty?" I thought, "What does that mean?" So I looked it up:
milty (n.) full of milt
"Okay," I thought, "what's milt?"
milt (n.) fish sperm
Now all I can think about is stuff full of fish sperm—yick! How do you stop thinking about something like that?