ok, so in BBS Ventus meets, Pete, Phil, Hercules, Captain Hook, and Tinkerbell.
In Days, Roxas meets all the same characters.
Roxas never met Hercules. I don't recall him really meeting Hook either (from a distance, Hook thought Axel and Roxas were Heartless).
But, yeah, pretty much, they just forgot because it had been over a decade.
Pete's an idiot, so he has enough trouble tying his own shoes, let alone remembering a face from ten years ago.
Phil has got rookies coming in and out all the time, I doubt he would recognize one that essentially bailed on him. I think Terra made more of an impression on him than Ven did.
And for Tinkerbell, who knows? Maybe she did recognize him. Might have just assumed he was another Lost Boy wandering around Neverland. Not like we'd know, though, considering she can't talk. It's probably why she trusted him in the first place, she thought he was Ven.
But for those who did forget, this isn't the same case as it was for Sora. Aqua very much knew who Ven was
eleven years after (in the Dark Realm), so if anyone forgot, it was a natural process.