Mids comes from partly the strains not producing as much THC and also how its handled/stored. if you store dank just out in the open it starts to lose potency and also if you brick it up to transport which happens alot it loses very much THC.....when it goes through dealer after dealer down to someone who finally smokes it it loses THC and crystals.....basically mids at one point was decent weed in most cases but through handling and poor care it loses all of its goodness(for lack of a better word)