Fat experiences

I often see people talk about "adjusting to the weight". I think the idea is that after a large gain some people want to maintain their new weight for a chunk of time so that the body can adjust to being bigger and heavier.

But my question is, is that a real thing? Like does your body ever actually adjust to being heavier or are things just permanently more difficult without weight loss?

Some things must be improved and maintained, like walking and stamina.
Others, like bending over to tie your shoes is something that goes and can't get back.

I've always had a slow gain, but when I always notice when I either gain or lose based upon if I can cross my legs easily or not!