There's nothing wrong with being a beginner if you're honest about it. We all were once.

But there's a difference between being a Dom, which is the way you are, and being a Master, which is what you do. There are probably even more definitions than FR mentions, but I like the simple practical one that I call the Caesar test. It was said in ancient Rome that a man couldn't name himself Caesar, it was the legions that named him. In my opinion, a man can call himself a Master when his subs or slaves call him that.

That definition doesn't have an age limit, but it does imply a certain level of ability and achievement. If you already have that, congratulations, you don't need to worry about others' opinions. If not, see it as a goal to aim for, not something to demand.