Jack committed memery when he posted 'all your base are belong to us' on a pet care forum, as none of the users had any idea what he was talking about.
When you can't remember seeing a dank meme although you are certain it has been processed by your visual cortex on a previous occasion
Dave: "Oi Trev, check out this dank meme!"
Trev: "I'm 420% sure i've seen that dank meme before, but I can't be sure"
Dave: "You must have short term Memery loss mate"