I just needed to share my post workout victory

I didn't run this weekend.  Saturday I went Bridesmaid dress shopping and didn't have enough time and when I woke up Sunday it felt like nine degrees outside so I stayed cuddled in bed.  So my last run before today was Thursday, not too bad.  But today is my first below freezing run of the year, so needless to say I was a little worried.  I had purchased new leggings that I've been waiting to try for two weeks!  They're fleece lined and by far my new favorite.  I had set out to complete two or three miles, but shortly after beginning my run I changed my mind to four.  First mile was a 10:17 pace, not too bad but I figured I would burn out like I always do.  My huge problem is starting too fast and then fading very, very quickly.  But I was wrong.  mile two came with a 10:05 pace.  What was going on?  During mile three I had felt my speed slow.  My Garmin beeped and told me my third mile was done in 9:53!!  I have never had a mile be under 10 minutes that wasn't a first mile.  I thought I gave up at 3.22 miles and once more during the fourth mile.  I literally stopped and turned off my watch, but in a couple seconds told myself that I could not quit.  I felt like I was barely moving towards the end of my run, and that last .2 miles was a big struggle.  I felt like I wasn't moving but I also knew I was pushing myself to be done, it was a weird feeling.  The final mile was done in 9:22!  Two weeks ago I struggled to complete four miles in 45 minutes.  Today I did it in 39 minutes and 40 seconds!  I don't know what happened and I'm not sure that'll ever happen again.