I worked with a few of my friends who smoked the weed and they scared the hell out of me forgetting where we were working in the high iron of a new building welding supports. We were tied off most of the time but there are times when you need to move and walk the iron to a new location. I saved them many times from walking off into the air ten stories up. I have refused to work with smokers before because of this trait of forgetting. Maybe in an office but never on a construction site.