Pokémon Nostalgia

Why is it that when ever someone talks about Pokémon, a smile comes across everyone else's faces. I know that Pokémon affected me, so I have chosen to investigate what it is that made people love Pokémon so much, and still love it now. Was it the friends you played with, the technology at the time? I hope to discover the answer to these questions in my research, and then maybe play more Pokémon.