Right now we have 5 and we use them all. We both have two pillows for our head and one long body pillow that runs the length of our bed under our head pillows. We used to have 13 pillows. I prefer that.
Wow, so many people use a lot of pillows at night! We only have 2 pillows on our bed - one for him, one for me. Sometimes he'll grab a second pillow to prop him up if he's feeling under the weather, but that's rare.
I have a ton of them but I do have back and knee pain so I end up using a lot of them. When I was younger I never had all of these pillows, lol. I don't do accent pillows. They are for function's sake.