I go through this over and over with ponies, especially G3. There's just so many, one can get overwhelmed and not be able to focus on them individually until you see a certain picture that really allows you to see that one pony's beauty and then I'm like "I have to have that one!"
Likewise, I've done the opposite, too. I saw one that I thought I really wanted, but when I had it in my hand, I didn't like it as much as I thought I would.