As Jason already explained, there's a legitimate reason why a dojo wouldn't allow you to "follow your own inner needs": because doing so would cause injury to you and others. I'm not talking about a few bruises, either, but joint injuries that can have permanent effects (and likely will, if you're 40 years old). It may well be, though, that you are one of the many big strong guys who just keep saying, "I don't believe it, prove it to me," and who only find out too late that they were wrong -- after someone is seriously hurt.