I'm in the same boat. Smoked all day every day for years and eventually became the same driver whether high or sober. I'm a pretty damn good, defensive minded driver with a track record to prove it.

That said, I didn't take my first bong hit ever and get behind the wheel. Drug tolerance and effects vary highly amongst people. I happened to be someone who became comfortable driving stoned over time, and it also made me extra vigilant, yet comfortable, behind the wheel.

I was obsessed with snowboarding during that period of my life, and drove 150 miles 20+ times a season through horrendous mountain conditions for like 10 years straight. Never not stoned. That gives plausibility to the idea that some people can pull it off, in my opinion.

One other thought. If I had been behind the wheel when taking my first chew, I would have been a hazard on the road. People do that shit all day long though, because their bodies have adjusted to the drug and normalized it's effects. I don't see people getting up in arms when they see me with a big dip in my cheek while behind the wheel nowadays...