Yes you can. esp. if not kept in the proper conditions. I've had seeds 3-4 yrs. old sprout. but have heard (will not say I buy it) of some grows around online with old sativas bagseed being 15 yrs. old.+ and sprout but I'm not sure if thats a fish story or not.
trick is for storage dry in an airtight canister (35mm film container is perfect ). some silica (like in electronic stuff that little white packet) or a few grains of dehydrated rice. This will keep the moisture content down. put in crisper drawer of the fridge (thanks hick). will last much longer.