Leg Lifts

My question, please don't laugh at me, is: our Border Collie is now 1 1/2 years old (had him since he was 8 weeks). He isn't lifting his leg yet to go potty. Someone told me that he must learn this from watching another male. Others have said he'll do it when he's ready to. I certainly don't mind that he isn't lifting his leg as it's saving my shrubs and flowers from being piddled on. Is it normal for a mature male that doesn't lift his leg at all?

Male dogs do not have to be exposed to other male dogs that lift their leg in order to learn to lift their own leg. It appears to be an instinctive behavior. And yes, some males may never actually develop the behavior - especially those neutered early on.