I had the egg in Pokemon White. I was expecting some totally badass pokemon (in other words, I was hoping for Zorua), and it hatched right before the final gym battle. In my head, I was screaming "ZORUA! PLEEEEEAAAASE BE A ZORUA!" Then I saw that I got Larvesta instead. Shocked and dissapointed, I named it WTF. I considered putting her in the box, but since I was technically her mother, I forced myself to raise her. I decided that I might as well give her a better name, so I called her Rin.
Before I knew it, she had become my favorite pokemon in my team.