People that smoke dope daily, are chosing to go through life with a cognitive handicap, regardless of their education or how mamt degrees they've earned.
And sorry but I'm calling BS on your'e alledged pot smoking PHD acquaintances.
Engineers are a pretty specific brand of individial. I know because I've worked for several Aero-Space Contractors for the last 20 years.
They are typically, quiet, highly intelligent and some are even borderline High Functioning Autistics, who take their abilities, knowledge and intelligence very seriously.
Too seriously to throw caution to the wind and engage in a self destructive behaviour like smoking dope.