I've seen several people that thought they may have had it because of some bad illness they had last winter that went on to get an antibody test. All of them came up negative. I think KT on the other board had a similar experience.
Remember, back in March/April you couldn't get a test unless you were sick enough to need medical attention, and had symptoms enough to possibly be Covid. Many were also giving flu tests prior to Covid to rule that out BEFORE you could take a covid test. Even under THOSE extreme conditions, only 6-8% of the tests coming back in our state (where the above was for sure the policy) were positive.
This means the overwhelming odds are against anyone that wasn't tested as actually having had it. Last winter was a terrible cold/flu season with several strains of bad shit going around. I had something bad in January, but I'd bet it wasn't Covid.
An ex-GF of mine had it (she's a nurse so yeah) and of course people at the hospital I work for have had it, and at least one died from it. I do not have any close family or friends that have had it.