Why do people say your conceited when you say your pretty?

It's because modesty is a virtue and if you're beautiful and know it, you shouldn't say it because in this society saying something like "I'm hot!" around other people is kind of bragging. You're telling yourself you're pretty, no one else is involved in that statement so no one else needs to be around to hear you say it, so if you say "I'm so pretty!" to someone else, it's as if you're bragging that you're better than they are and it's not good character. It's great to be confident and act like you like who you are and you can tell yourself that you're pretty, but don't tell others that you're pretty. Unless of course the person's doing that because they want others to notice that they look good, then it's actually a sign of low self esteem because it means their confidence is completely dependent on other people and actually does NOT make them come off as confident. Just rude.