Blowing off Steam

We started a new toddler tumbling class at the Y today. I was really excited about it and thought Jack would really like it, but once again my high expectations were my downfall. Jack loved parts of it and hated other parts. He threw several tantrums and the "teacher" just seemed to make things worse. She kept asking me if he was teething or if he missed his nap or what is making him so upset. Look lady, my kid doesn't like being told what to do, especially when it means he has to stop doing what he's having so much fun doing. He doesn't like a roomful of wild strangers and he doesn't like strangers getting up in his face when he's trying to throw a tantrum. He's 1. Isn't this all fairly normal? And no coming to class early will not help him be more comfortable. As much as I would prefer to just never go back I know that's not the answer. I know that if we keep going he will get used to the routine of the class and he won't get so upset. But I needed to vent.