When things got stressful at work I started smoking cannabis occasionally. It was really helpful to my overall mental well-being. It was great for stress, and made me feel wonderful, and it severely enhanced the creative part of my mind.
Then I went to the mall high with a sober friend - and had to keep him from getting distracted in stores and keep him on track to buy the item we needed. That's when I realized I was High-functioning. (True stories.)