seeing Hashem's goodness

 המאכילך מן במדבר למען ענותך  What kind of suffering could there be in having mon to eat?  The gemara in Yoma (74b) comments  אמר אינו דומה מי שרואה ואוכל למי שאינו רואה ואוכל אמר רב יוסף מכאן רמז לסומין שאוכלין ואין שבעין If you thought of steak when eating the mon, you tasted steak, but the food still looked like mon; therefore, a person was never fully satiated or satisfied.  From here, says the gemara, we learn that a blind person who cannot ever see his food never really feels satiated either.

I saw quoted in the name of the Damesk Eliezer that this is why we daven on Yom Tov שׂבּענו מטובך.  We don't just want Hashem to give us טובה, all that is good for us.  He does that all the time.  The problem is that we don't see His goodness for what it is, as we live in a world of hester.  שׂבּענו מטובך -- we want to be able to see the goodness, not just believe in it, as only then will we feel satiated from Hashem's blessing.

הפּסח נאכל על השׂובע.  The korban pesach was eaten only after one was satiated and full, as a desert.  We have to be satiated and full from Hashem's goodness to truly take away the message of Pesach with us.