Funny, we just bought a new mattress. It came with a memory foam topper, so it's higher than our old mattress. Last night was the first time sleeping on it and I had that floating sensation. Also, our smaller doggo had a hard time getting onto the bed.

Once I got to sleep, though, I slept very well. The old mattress was really saggy and my back and ribcage sometimes hurt when waking up. In contrast, I feel great this morning.