I have a funky "gift" of being able to look at an opening in a cabinet (I sell lot's of TV's) and call out the measurment within 1/4".
While I intuitively know that the metric system is far more practicle and efficient, I'm still having a hard time teaching my brain to work that way. I still find myself "converting" the measurements.
This is not unlike being able to speak Spanish, but not fluently. I have to translate, formulate a response, translate back, and then speak. I can't think and respond in Spanish natively, nor can I "think" in metric.
I hope I overcome this, but I still find it difficult. I have a few basic units (conversions) memorized that I don't have to think about (3/4"=19mm as an example). I have a dual unit tape measure in my shop, but I think I might be better off ditching it and going straight metric. I think it would also help to ditch my imperial tape in my tool kit I use for work.
Guess I'll be doing some shopping this weekend.