Decision made

I set off for my 7 mile run thinking I would go for 70 minutes. So far I have based my runs on a 10 minute mile with the hope that I was going faster, but figured a little extra couldn't hurt. I went to the Bosques, then did a lap around the Japanese Gardens and was on the home stretch or so I thought. I looked down at my watch and I still had 20 minutes to go! 10 minutes maybe, but I was shocked at 20. I was convinced my watch had some sort of glitch, but as I left to run for 70 minutes and I was going to stick to it. I finished my time and was thoroughly confused. I wasn't exhausted and actually felt really good, but was dumbfounded as to what had happened. I checked it out on MapMyRun and found out I ran 7.6 miles. That at least made me feel better, but it's also motivated me to start mapping my runs beforehand. So next Saturday I'm off with a guided route.