What do you do when you lose your job, your car, your girlfriend and your slice of pizza all in the same day? You grab your best buddy and join the U.S. Army, of course. Director Ivan Reitman pitched this now-classic comedy as “Cheech and Chong Join the Army” and Paramount greenlit it about an hour later. Bill Murray and Harold Ramis are great as two guys who enlist for no other reason other than there’s nothing much else to do (and to meet girls — P.J. Soles and Sean Young, in particular); you also get John Candy engaging in the fine sport of mud wrestling and the late, great Warren Oates in one of his final performances as the boys’ hardass drill instructor. Stripes only stumbles a bit in the third act when it suddenly thinks it needs to have something resembling a plot (involving a bunch of nonsense about “borrowing” a top-secret military vehicle and ending up in Russia) — other than that, it’s comedy gold.