Riku's kind of in the same boat, though he decided fairly early that returning the opals to their assumed rightful owners (or pitching unknowns into the lake) was probably the right thing to do. Otherwise, it just feels like prying into other people's business. Admittedly, he does end up with an opal or two he hangs onto simply because of personal and/or sentimental reasons...

Humans have their weaknesses.

"That's an even longer story. The short version is Mickey set out to search for a certain Keyblade," Riku explains, resting a fist against his hip, "Meanwhile, me and my friends were trying to build a raft to leave our world and see what else was out there. I," he hesitates, "Am not really proud of how what I did to leave, but while we were separated, I eventually ran into Mickey."

He's just gonna... yep... gloss over huge amounts of important plot points... what can he say, he hates telling long stories.