This cannabis-infused brownie weighs 850 pounds, stands 15 inches tall and contains a whopping 20,000 milligrams of premium THC. Let the stoner jokes begin, along with a flood of recollections from people who tripped out on the heavily spiked homemade treats of yesteryear. MariMed, a multi-state cannabis operator, leans directly into the lore around do-it-yourself…