I dont know how I got mine, its just different skin pigmentation, my mom has it on her shoulder, and hers has freckles in it, I have it on my foot too, and it has freckles in it, but the stuff on my tummy is weird and is just dark, and I got it on my arm too, but its only a small mark like an inch long but its like weird shaped. I hate it when people go on maury and crap and cry about when they got it, when alot of people have it, and its not that big of a deal, I can understand when its really bad, but some of them people dont have it any worse than me... I hate people when they are all like "oh feel sorry for me, im two different colors"... Its like yea so am i, I dont care!