hahahahahahaha! Man, who says stoners don't accomplish anything? Anyways, though I won't say your wrong (and a lot of what you say seems right), I'm not sold on the idea that everything that makes stoners' do poorly on some tasks always boils down to the short term memory problems. I mean, the brain is so complex, it would be very hard to know without doing CAT scans or MRI scans, or other testing. One can argue "well, you're clumbsy because you forgot this or that" but it isn't definitive. It's just an opinion and argumentation at that point. No offence to your idea though.
no its understandable, i mean, its not like im a neuro-scientist i see it more as a case of philosophy though and while the brain is physically complex, the functions the brain makes are generally rather simple and as you said, we are animals, we only have some very small steps above them in our intelligence as well. as i went on about, -most- are result of our good short term memory