Yes I think I would actually agree there Mike, I was ill just once before back in niovember for a week and I thought I would lose all the base training I had done in sept/oct but it seems I came back stronger than before I was still more than able to compete in sprint sessions etc.
Strangley enough, the same happens with me after injury, when i have a few weeks off with little training other than circuits and maybe drills if I can, I often come outnwith a personal best. I think It may just be how my body works though.