It's a rib at the S&M folks rather than an insult. As for the rest of your comment, I've sent a PM.
To stay ontopic, forgettable Pokemon tend to be dead end Pokemon that have no use other than animal coverage in the Pokemon world. For me, that's Pokemon that cannot be caught during the natural course of the game and trained up as you play. I caught a Bellsprout and trained it to level 40 as I played, for fun. Pokemon like Farfetch'd and Mr Mime, require trades and are therefore not remembered by me. Neither can be evolved. It would also require losing an Abra and Spearow, both highly usable and evolvable ingame...