Bob Stone's true motives (SPOILERS)
So Bob Stone contacts Calvin Joyner out of the blue one random day and is all happy to spend time with Calvin. The thing is Bob had no one to turn to when he got into trouble with the CIA, so he contacted Calvin due to him being the only one who treated him decently in high school. It wasn't an idolism thing, as we see - Bob acts like Calvin is some superstar because he was popular in school, but Bob had nowhere to go and nowhere to sleep, he was homeless, so when you think about it he was just using Calvin.
It's clear that Bob's innocent socially awkwardness was just an act because when things get real he's as sane and as serious as a hurricane. So basically the friendship wasn't genuine (not at first anyway) maybe they become proper friends later because as we see - Calvin gets a job at the CIA, but up to that point the friendship was not a proper friendship.