From my experience those "little mysterious things" happening are always our gut feeling and instincts telling us that yes he IS using. The new friend he spends so much time with is most definitely probably an addict or dealer or both. Your not going crazy always trust your gut. My ex addict boyfriend would always say that guys he was hanging out with were for jobs he was doing so I would question myself and not want to stop him from work opportunities. Every time I was right that it was a dealer or addict friend. Once he spent all his time with ...according to him, a friend he had met through his grandmas church that ran a recovery self help group. You have got to admire his creativity. This guy would pick him up. He looked pretty square and my ex said he had a good job and I would be crazy to think he is using heroin. I checked like the little investigator I am and although my gut told me this guy was a dealer it turned out he did in fact have this good job so I thought oh I am crazy and I shouldn't stop him from hanging out with this guy. Well, guess what? The guy turned up on the news for getting caught selling heroin and meth in a seedy hotel room. Because of his public job they really blasted him on the news. Always go with your gut !!