Right, a nice happy family.
He starts out being completely lost and bewildered. Thrown into someone else's life. Always living a lie, always being the intruder, the imposter, the voyeur, the liar.
A lifetime where he has to deal with the loss of his real friends, his real family. He is all alone, standing in the middle of a crowd. If he talks about it his fake friends think he is insane. Anyways, he slowly looses his real self and assumes the identity that they tell him he is. After several decades of seeing your life's work come to naught, making attachments to fake friends and fake family members, after watching those friends die, after knowing that your world will soon die, after growing old and feeling the infirmities of old age seize your body and mind as you slowly decay--well he leaves it all. No, screw that, screw those dumb ass aliens, and screw the script writers.
6 Star Admiral of the Loyal Water Buffaloes and Honorable Turtles