Right so I've been told if you smoke outside or if you have windows open the smell will disappear shortly/very quick but I've been able to walk outside in certain spots for maybe an hour or something (once on the way to my journey and once back) knowing someone has possibly smoked in this spot before? also reason why I'm asking is because I live in lower levels of my flat and if I were to smoke I don't want the outside of my flat to smell of weed because the neighbors might know.