Good point Mehdi, understood.
I think the point underlying what I was trying to say is that a situation you find yourself in cannot make you unhappy or miserable unless you choose to let it. Within reason it is possible to choose how you act and react in any given situation and if you go along with someone else's request, and then are determined to be unhappy and not enjoy it because of your preconceptions of that activity, you will be unhappy. Your reality becomes what you think, as you put it.
On the other hand, if you agree you do something but decide to enjoy it anyway, since you're there, you can do so. A situation is only a sacrifice if you choose to see it that way. It could just be an unexpected treat, depending upon your disposition during the 'family visit' or whatever. You could get something really positive from the visit that you couldn't have forseen, like a job offer, gift etc. The chances of a positive outcome would be reduced if you went with the negative attitude.
With the sex example, if you have fostered an attitude where you 'don't care what happens' you wouldn't be pissed about the refusal, you would just take the opportunity to get extra sleep instead or do something else. It's not the end of the world and could be an opportunity if you choose to see it that way. Maybe you go downstairs and call up an old friend for a chat, which you wouldn't have done otherwise and that has a great outcome, even if you just make each other laugh for a while.


