THC only stays in casual smokers body for 4 or so days?

"4-7" days? For light smokers? I thought it was 30 days no matter what?
taken from here

Nope, if you don't smoke weed that much, when you do it's not in your system that long. I am an All day every day stoner so it could stay in my body up to 90 days. If you weigh more it will stay in your body longer. THC hides in body fat. That's my theory as to why we get the munchies.