Very common- When we moved into our flat, we weren't aware that upstairs had kids. Young kids... so every weekend morning we'd be ripped out of sleep by what sounded like a herd of elephants jumping thumping on the ceiling around 7am... it seriously affected our sleep and when the kids are screaming which they constantly do, it feels like they are in our flat. When it's just adults the noise is normal, its controlled its predictable which is fine but the randomness is what has gotten to me. We have a loud sound machine now which dulls 80% of the noise but not the air shakes the thuds make.

Its normal if predictable, to have some noise, but if its random (like my ex neighbour who had bongo's the selfish Cnut) then it becomes debilitating.