It could mean a few things:
1. They are bad people. Bad people say bad things.
2. What they said about you could be true.
3. They might be projecting some unrealistic expectations on to you.
4. They might be projecting their insecurity on to you.
5. Their mom didn’t teach them good manners.
6. They don’t feel great so they have to say something bad about you to make themselves feel better.
7. When people say bad things about you, it always says more about them than you.
What would you add to this list?