Yes, but also no.
By definition, a superstition that is valid is not a superstition. "Red sky in the morning, sailor take warning" is usually not called a superstition, because it is a good heuristic. "13 is unlucky" is called a superstition because it is not useful.
Things that might be a 'useful superstition' include:
Obviously, the truth value of these is variable and often requires a generous interpretation. Also, some (all?) of these are only useful to people who want easy rules, indicating that they aren't really LessWrong types.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.