Tempo 10k - you regret the things you didn't go for

I did Tempo 10k in Eastbourne at the weekend and I ran 39.30, down from 39.55 last year, and this year it was much hotter than I like and there was a strong headwind going to the hill. 

I don't look at my watch ever really, certainly not while racing. I've made the mistake before of missing out on times because I have been following my watch or I've gone too fast sticking to what I think I should be able to do rather than what I can do. I bring this up as at the start of the 10k the wind was behind us and the lead group set off fairly slowly so I tucked in at the back and dropped off when they picked up the pace. The result was me running 5k PB pace from a flat course at the start of a hot, hilly 10k. Not that I realised at the time. 

I found myself with the option of going for it and having a chance of 5th or hanging back and going for 7th again, as that's where I came last year. I didn't realise this at the time either but I decided to go for it, I was feeling good and it didn't feel too hot. Myself and one other basically went back and forwards until 8k. At this point I had overtaken him and was in 5th and chasing down 4th and then on the downhill everything just went. I think I overheated and I probably had set off too quickly. I was disappointed to finish down in 10th but upon reflection I gave it go. 

So I went for it and didn't have it on the day. Given the conditions I was never on for a PB anyway so I didn't really lose anything by giving it a go but had I not tried would I have been wondering what could have been.