I'm the dumbest person to walk on this planet

• I just can't process any information, my brain sucks, it can't do anything other than being addicted to stuff, however much i try to learn i can't retain
• it's a shame that I even reached inter, i cannot recall concepts of foundation (yesterday someone asked about bailor and bailee) and I just mysteriously forgot everything
• i don't even remember basic P&C formula, sometimes even accounting principles (I cannot even recall the basic companies P&L format or CFS)
• In inter, before starting I made myself and promise that I am going to learn shit load of stuff to it's perfection (accounting principles, basic accounts, FM theory, everything under the sun, so I don't feel disgusted at myself)

I didn't, please can someone tell me how to recall everything even after a hella long time? Is it something that i have been left out of?