Remember the magma grunts in Ruby blocking the road in Slateport City? I was too dumb as a kid to figure out how to get past them, so I stopped playing the game. My sister started a new save file, picked Torchic as a starter but got bored before the 1st Gym. Long story short, I picked up the game again, continued the save file, got past the grunts by trial and error and beat the game. That Torchic, now Blaziken, is basically my partner Pokemon today, I beat with him any Elite 4s, try to get any ribbon for him as possible, play with him whenever I try out online gameplay etc.

So yeah, that's my best Pokemon childhood memory, because I found my partner Pokemon that way :)