How many bolster does a person needs?

How many bolster do you have? Most people only have one bolster but I have 2 bolsters. I used to not sleeping with a bolster at all. Since I had my first baby, I have been having 2 bolsters with me. One to put behind my back and another to support my baby's back or mine, when we switch places. Wonder why? I breastfeed my baby to sleep and this goes on the whole night. That is the reason I need 2 bolsters.