I have a 3.8 undergraduate GPA with almost entirely A's in all courses. After obtaining my undergraduate degree, I took courses for fun in various subjects at two remote graduate schools. Because I was working full-time, I was exhausted a lot of the time and didn't focus on the grades. I got mostly B's, although I withdrew from a course or two when I couldn't handle both work and the courseload at the same time. I didn't get a degree but really enjoyed learning new things.
Now I'm applying to graduate school and have a real problem. I'm applying to top programs and applications want me to submit transcripts from all programs attended, but my grades on these "freelance" graduate courses are quite poor. How can I explain that I took them for fun and knowledge, and didn't focus much on my grades, but I'm very capable of getting good grades if I want to?