I'm sincerely asking adults to stop being even a little self deprecating in the planetarium.
You do not have a "stupid question" you just have a question.
It discourages children from asking things.
It's okay to ask questions and you don't need to feel bad about doing it.
When you have a chance to ask a question, take a deep breath, and just ask the question.
If you're shy you can come up after and ask without the audience. That's also fine.
Being curious isn't shameful. It's okay.