When I was a kid I got FireRed as my first Pokémon game, and my brother got Ruby. We had looked up the Pokédex and saw the Johto starters and wondered how you got them, and we knew LeafGreen and Sapphire were the counters to the games we had. So we decided to buy Emerald, one for each of us, and thought it'd be the game with the Johto starters. We were disappointed (but not for long).

Additionally, my brother never used female Pokémon; not because he thought they were weaker, but he just never did. When we started Emerald in the car on the way back home he ran into an orange Zigzagoon, which was female. I saw it as a gender difference, and my brother saw it as a Pokémon he wouldn't catch. Afterwards we saw another female Zigzagoon and it was brown like the others. Only after learning more about shiny Pokémon did I realize what happened.