Wow Peter, that's a great time!
I have had a couple of rubbish runs recently, not sure if anyone else has experienced those yet? Last Saturday went on a 'long' run, which was rather curtailed by most of the footpaths that I planned to run on being shut by the NT for some reason (on the beautiful Stackpole Estate, Pembrokeshire), and I just couldn't seem to get into any sort of rhythm, ended up doing 4 miles, but walking too much of it. This had been preceded by a solo 3 miler where I went out much much too fast and ended up completely knackered by the end of it.
Anyway, undeterred, I stuck to my 'plan' (running three times a week wherever possible), went out with the beginners group on Monday night, and it was great! Settled into an easy pace, covered 4 miles, and could have gone further. I suppose it's like anything, we'll have good days and bad ones.