In all honesty, I suspect we all do from time-to-time. Aching legs, tired lungs, feet that shout at us to stop...
I have just come in from W2R2 and I feel good, but it's not as easy as when I graduated - for lots of reasons. Then I turned on my TV and on came the AJ Bell London Triathlon... A lady was being assisted out of the water at the end of the first event and was being helped in transition before the bike ride. She is a quadruple amputee and has also climbed Ben Nevis.
I have legs to ache and arms to swing around. She doesn't.
I feel so small and humble when I think about my aching limbs, limbs that for her can never ache again. I feel so small and humble when I think about my sore toe, toes she no longer has. I feel so small and humble when I think about my hands and when to do with them when I run, hands she has no has.
Please, don't think I having a go at out aches and pains, our tiredness and troubles; I am not. We all have these, and I'm sure that she grumbled in just the same way before the amputations, but it does show just what we can achieve when he put our mind to it.
Good luck to all the runners out there and keep going. Whether you are a newbie, a lapsed grad (me) or a very experienced runner, enjoy every minute and make the most of life.