Seriously, HOW do some women not get stretch marks!?? I've done everything that everyone has told me…

Seriously, HOW do some women not get stretch marks!?? I've done everything that everyone has told me to do to avoid them, but my entire stomach, sides of my waist and my thighs all have stretch marks like crazy. I mean, they are totally worth it, for the tiny little life my body is bringing into this world, and I will own my marks and never be afraid to show them, but I just want to know how I keep seeing pregnant women without them! Lol. 😛