It all depends on the expectations I suppose

Take pain level x and mobility k

If you expected just after surgery a pain level y (y being bigger than x) and mobility l (l being smaller than k), then you feel optimistic & energetic. If after one week you expect a pain level less than x and mobility greater than k, then that same experience becomes a source of frustration and disappointment. Bleh.

While in the end it's just the same experience, right? So I just need to convince my mind.