Most people don't put a lot of time and effort into studying their thoughts and actions, especially whether they're consistent.
Which means that if you worry about others' opinions and judgment of you, you'll most likely notice that other people are doing and saying things that sometimes include silliness. If they were as sensitive and thoughtful as you are, they might have reason to be concerned about what they said.
So while they're judging you for something not 100% "appropriate" - or maybe you just think they are - these same people are "guilty" of doing the things they judge others about. They just believe that their speech and actions are always appropriate.
This is a slightly convulated way of saying that because they don't doubt themselves, they don't examine their actions as closely as you do, and as a result they feel free to do what they want.
Maybe you can have the best of both worlds. Continue being self-reflective while also being
confident. We're all entitled to some silliness and we all have foot-in-mouth moments. Just be sure to notice your other moments as well.
This is a behavior often misunderstood by those who want to be a good person and are trying to be helpful and compassionate.
It's obviously a good thing to want to be kind and considerate. And to be understanding of people who are in distress, including, sometimes, those who behave badly. You want to be tolerant of their predicament.
This becomes a problem for you when you become an enabler and allow someone to take advantage or otherwise be harmful. Adults are responsible for their own behavior unless they aren't capable of doing so. If they fail to work on their issues, that's their responsibility not yours.
It can be difficult and painful to watch them struggle. You may feel their pain intensely. But some people will never resolve their issues, despite your efforts.
Remember that your wellbeing has value beyond being an enabler or a martyr. It's in your best interest to set and maintain boundaries. And there may be unpleasant consequences.
Only you can decide how you want to interact with them. Depending on the situation, you will eventually have to ask yourself how much longer you're willing to place your own health in jeopardy.