There isn’t an example of a desire not having a satisfaction for it or a possible satisfaction for it? By my light at least. Feel free to provide any counter-argument. It is not merely a lack of evidence = it doesn’t exist though. There is positive evidence that desires have possible satisfactions for them. Also, we don’t really prove much in life so to ask that is to set a standard beyond what anyone can achieve. It is beyond reasonable doubt though.
That is a good point and I will admit I am guilty of that quite often. However, I think it is also valuable to defend arguments or at least to be able to defend your arguments if you are talking to someone genuinely questioning for truth.