I've learned so much in the last nine months since I started running and the main thing is to trust my body and not to trust my thinking.
Today I was sure I'd run appallingly. At the midway point I thought I was ready to stop. I thought my legs were telling me that they couldn't go on. I was quite certain that I was running at the sort of pace I was at when I first ran for more than twenty minutes and that I should give up rather than the shame of finishing so badly.
In fact, my legs could go on and so could my heart and my lungs and they did get me round again and I was only about 20 seconds slower than last week, but my head was telling me all sorts of shit, pretty much all the way.
Shut up!