I'm curious has anyone here ever taken a course in logic? I have to say it was one of the most useful classes I ever took. Even though the course credit did not count towards my major or minor and I took it only for 'fun', it has proved its worth many times over. I can no longer read a letter to the editor without instinctively dissecting it. I look upon it as a life skill. Chemistry is another subject I'm glad I took a couple of classes on. I did quite poorly grade-wise and I've never needed to recall any formulas for calculating molarity. It's worth to me, however, is in terms of it how it laid a foundation of my understanding the physical universe - gave it some sort of referent if you will.
What are some of the most useful classes you've ever taken and why do you value that knowledge today?