Here are just a couple of signs of stupidity, or at the very least, cause for concern:
1) If you're asking, "Does my butt look big in these jeans?" - you are one of two kinds of idiot:
a) you know your butt looks big, but you want to be lied to anyway.
b) you know your butt looks fine, but you have self-esteem issues that make you need someone else's approval.
2) If you are the only one laughing at your joke, feel free to conclude it's bad. If you tell it more than once, you're an idiot. Make yourself laugh on your own time!
3) If you don't recognize sarcasm and derision, you may miss several attempts to alert you to your stupidity.
4) If you don't know the difference between they're and there and their, or your and you're, or then and than, then you are, in fact, already an idiot and beyond help. You need not read on.