I have bought the incorrect ticket and swapped theaters at the last minute. Sometimes intentional, sometimes changing my mind. I movie hopped a bit as a kid too. But I'm one who has always actively supported the movies and so I don't think it's a big deal. I was a kid and even though that was technically incorrect behavior, that activity has fueled my love for films later in life and theaters and movies have benefited from my many dollars spent since! Bigger picture = let it go.