Your first breeding line

All of us started somewhere and for most of us that was a group of pet shop mice. I'd like to here every ones stories of their first line of breeding mice. How long did you work with the line? What were your initial goals? What did you learn from them? And just general stories about getting started.

For me my very first line was a trio of pet shop mice a poorly marked dutch, a black and white piebald and a black tan. I learned that mice can have great personalities and that genetics can be a pain in the butt I also learned that 19 days can be an eternity. Unfortunately being from a pet shop health was not the greatest one doe died after 6 months and the other doe passed away with birthing complications. I made another attempt at breeding but with the same results. I was finally able to find a breeder getting out of mice and I look forward to working with my current line well into the future working towards improved size and health.