@vikorr,
Let me clarify-
I've just been bedridden for 3 days with a fever, chills and bad headache, unable to eat, and sleeping semi-deliriously on and off round the clock.
I took aspirins which helped the headache a bit, but on the whole i certainly wasn't happy, but there was absolutely nothing further I could do about it except soldier on and ride it out.
I accepted the situation, and that acceptance gave me an inner peace and balanced out the unhappiness to some degree, what more could I do?
Same when my mother died 14 years ago, I was unhappy but said to myself "Okay she's gone and is never coming back and there's nothing I can do about it", so accepting it gave me some peace and I just got on with my life.
My point is that if we can't do a thing about an unhappy situation, we can at least often lessen the pain by accepting that we can't do a thing about it.