Patur Aval Assur,
In your first paragraph, what is the benefit if not the pleasure?
A person may not know what the benefit of his action is.
In your second paragraph, you don’t explain what the benefit of following the command was.
That’s right! There was no apparent benefit to him whatsoever. Hashem had already promised everything to Avraham that he could have possibly wanted, specifically through Yitzchak, but then Hashem requested him (??? ???) to bring Yizchak as an offering. Avraham did it simply because Hashem asked him to, because he believed that if Hashem asked it, there was benefit to it.
My point from the terrorist is that as long as you think you are fulfilling your purpose, you have the same “good feeling” regardless of whether you fulfilled your actual purpose. (This is based on your assumption that the terrorist feels good.)
So, what’s the question?