Too many! When we moved house about 8 years ago we discovered we had 21 sets of bedding - 18 single (for 4 single beds) and 3 sets of king size. I massively reduced them, but I fear they may be increasing in number again.
We now have 3 singles and I think 11 sets of single bedding (off the top of my head), 1 double with 3 sets and 1 king with 3 sets.
and I’ve just remembered that I’ve bought the DTs new bedding for their birthday coming up.
What can I say? I like buying bedding
(In my defence we have got through at least 3 sets per bed in a night before when a sickness bug took over all 3 of our girls. They are now all much older and definitely capable of getting to the bathroom!)