Wait, you're telling me that in heaven they get rid of the sad parts of our existence and we're permanently happy and you're not okay with that?
Yeah, because when I feel down, or angry, or frustrated, there are usually reasons for feeling that way. I feel sad because someone I love is lost to me, I feel angry because someone has wronged me, I feel frustrated because I want to get something done.
You could argue that in Heaven you simply have nothing to feel down about, but as we've said before, if loved ones aren't with you, you should feel sad (If I didn't I'd feel really guilty about insulting their memories. If I didn't feel guilty then I wouldn't be me.) . If you've got nothing to strive for and nothing to do, you should evenually feel bored.
I doubt that your self is merely your earthly desires. Simply losing those desires doesn't necessarily mean you lose your identity. Besides, you change yourself countless times throughout your life, what was important 5 years ago probably isn't so important now to you, why couldn't your spirit go through the same type of identity shift and still be you?
True, I'm a totally different person to how I was as a baby, but that change was a gradual shift to achieve continuity, not a sudden seismic shift from baby to fully-blown adult. If my future, heavenly, self was changed so much to not care about the suffering of others, the loss of loved ones, stymied of curiosity to prevent boredom and happily settled in what amounts to a permanant drug-fuelled fog then I don't want to go to Heaven because I don't like the person that I'll have become.