I still think cops suck. Doing their jobs or not, the vast majority of them are power abusing jerkbags. Irrelevant, I know, but props to the 1% of law enforcement officers who are honest and just doing their jobs. I don't know why, but I always have to throw that out there. I think I just know too many cops who run meth labs on the side.
Is marijuana prohibition ridiculous? Yes. Should weed be legalized? Absolutely. Until it is, should people who are caught with it be treated as if the law does not exist? Absolutely not. That being said, should it be treated as a lower priority for law enforcement? I think so.
Just think, if you weren't carrying cigarettes (arguably legal) you wouldn't have been caught with weed (inarguably illegal) and could have refused a search of your private property until probable cause was established or a search warrant issued.
Speeding: Technically speaking, even 1 mile per hour over the posted limit gives the officer the right to pull you over. However, most police officers won't bother unless you're going at least 5 over. I think TheKid is probably right about there being something about your ride (or maybe just you) that makes the cop thinks he's going to find something. Perhaps the force is just strong with him, who knows. Moral of the story is: As Jellybean said, if you're carrying illegal contraband, don't speed. Use your blinker. Stop at stop signs. Don't run over pedestrians more than once. Don't litter.
Hope you had a happy birthday, though.