Empathia: I'm not sure your description warrants the label? (For newbies: "Doing a margaret" is behaving like margaret thatcher -pompously telling others what to do, dictating under the arrogant assumpion that you know what is better for them more than they do and it's 'for their own good'.) It's a problem many schoolteachers suffer from, and also religions people.

"I only want to free your mind", they cry, blissfully unaware that their real job is to learn how to mind their own business and get on with freeing their own.

It doesn't sound like you were doing a margaret. But you maybe did forget that people like to live in peace with no hassle, just as we like to live in peace without hassle from them, and on the whole they're anxious. To anxious people noise and apparent distress gives them hassle. They start worrying if we'll be violent, and they start worrying they might get blamed, and they start worrying because they don't understand.

So doing stuff out of the ordinary in public places does make other people anxious, and we're not supposed to be doing that, because they'll often either react with fear or violence and give us more hassle than we started with, for example calling the cops.

So behaving in controlled ways in public places is not only better for others but better for us. Developing rectitude of behavior and social politeness and respect for everyone's space is all part of developing intelligence and also for our own protection. There is so much anxiety out there that if you accidentally kick it off, it can be like entering an ass-kicking competition with a porcupine  :  )

If you want to let off steam or express yourself in ways that might frighten others, head for the wilderness. The animals don't mind (in fact, they do it too) and it helps keep the humans away.

Re worrying: Any amount of worrying is too much; it's not something we're meant to do.
Best,
AR