When I started down the road after the oil change, I noticed that the radio was off.  Since most mechanics shut off the radio, I didn’t think much of it.  Then, I noticed that my clock was also flashing.  Then, I realized that the dead battery had reset everything.  So, after I had reset the time, I tried to turn on the radio.  But, the radio display kept asking me to “enter code”.  Since I wasn’t sure what code it wanted or even how to enter it, I deferred that for another day.  I just wanted to get home.