Lent has never been a big part of my life. I've watched as friends gave up sodas, candy, and/or ice cream for the six-week season with some sense of awe but mostly a "you're giving up what? and why?" attitude. Being a Unitarian-Universalist meant I was exposed to many other religions including Catholicism, but I've never participated in many of the more ritualistic aspects of Judeo-Christian religions such as confession, Lent, etc.
Unfortunately, that knowledge hasn't kept me from unintentionally and usually naively sticking my foot in my mouth from time to time.
Case in point: In high school, I once walked up to a classmate on Ash Wednesday and told them "in confidence" and away from traffic that she had a big smudge of charcoal on her forehead. I still remember the dumbfounded look she gave me. I couldn't tell you her name or even what she said, but her facial expression has stuck with me. It was the "OMG, did you really just say that!"
In my defense, I spent at least 2 hours of every day in the main art studio at my high school - so I always had charcoal, paint, chalk, etc. under my fingernails, on my hands and arms, and sometimes on my face. I was one of the "art students," so I really didn't care. I actually always appreciated it when someone told me that I had missed a smudge of charcoal under my eye or on the side of my forehead. This person did not.
I have since opted to check the calendar before offering up my two cents and a tissue to others with charcoal on their foreheads!