When I played my first pokemon game (Soulsilver), I didn't know shinies existed. I was going blind throughout the game. I found an green ursaring, and I thought my game was bugged or my eye sight was funny (I was almost asleep). Had to bring to my mom and ask if it was really green, and she confirmed.
I captured it with few HP left.
And only after that I discovered shinies.
I don't brag, but I like to remember this memory. Since I almost switched the DS off thinking it was a bug.