Once upon a time, I used to play pokemon emerald with just my starter. i mean, the whole game. I would just use my trusty ol' mudkip/marshtop/swampert the whole game. I would catch other pokemon but only for hms and such. We all remember the hellish may battle right before mauville, right? if you also picked mudkip then she has this annoying as hell grovyle that has absorb (which regenerates the damage I give to 'em). because I was stuck with my marshtomp, I had no choice but to grind to lvl 30 before I got past her.
course, i learned some epic team-building skills as I grew up :P but the memories whenever I replay Gen 3/6 Hoenn and I get to battle May in Route 110, both nostalgic and annoying really.