As soon as I was old enough to understand what “pledge allegiance” meant, I refused to participate. It’s antithetical to everything America was supposed to be about. Allegiance is something a subject owes to a sovereign. If you live somewhere that still has ties to monarchy like Canada or the UK, then it would make some amount of sense. In the US, however, it’s literally nothing more than authoritarian indoctrination.
Needless to say, that got me in trouble a lot, especially in new schools or with new teachers.