40 is certainly not too late. The important thing is to find an instructor who enjoys teaching beginning adults. I take several different classes in Los Angeles, and it took me awhile to find a mix of instructors who were good with adults. There is a huge difference in attitude between someone who's there because the studio has a time slot to fill, and someone who really wants to help you learn.
As for my fear of being seen in tights, as Doc said on another board, that fear quickly disappeared as I began to pay attention to how my body works, proper position, etc. And, hey, chances are there are others in the class who look worse than you, so get over it.
I find my classes very supportive. People are really dedicated to seeing you improve. It's a great environment for forgetting about the world for and hour each day.
Go for it. Enjoy. Let us all know when you've taken your first class.
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