Pokemon is seemingly based off of, but not intentionally, a surprisingly popular Asian sport from around the time of WWII when children would go into tall grass at night and find krickets. They were fast buggers, so these people used their own krickets from match boxes to attack them (they weren't very obedient, but trained right, they fought) and slow them down. The "weakened" kricket was then caught in a matchbox. Then, during the day, the same kids would train untrained krickets to attack other krickets, and pit trained krickets against each other.
As you can see, this is a lot like the Catch and Train part of pokemon, and not the collecting, which was inspired by, who was it, Shingeru Miyamoto, and his childhood collecting bugs in tall grass, caves, ponds, and anywhere else where you would be able to find a pokemon minus unda da sea and alternate universes (da torn w0rldz).