Ah, the notorious "bowl burn". In some circles, it is seen as a token of dedication to cannabis. Similar to a tatoo, but the fact that it is the actual outline of your bowl, burned into your skin, kind of gives it an added flare. A friend of mine gave himself a bowl burn, and is going to place a cannabis leaf tatoo in the center. I dont recommend them, but to each his own. Yours looks pretty deep, dont count on that going away for a while.