Why am I so prone to cysts?

They're gross, and I've been getting recurring ones in places *tailbone area, behind ear, ect* That never fully go away. They'll be kind of dormant, and then pop up. My doctor said surgery for the bad ones, and to leave the smaller ones since it'd be a lot to handle, but why do I get them? ): I don't have bad hygiene or eat too much fat, or anything, I don't get it.