Remember when you were younger? It seemed like you could run forever and never had to stop to "catch your breath". When I was working and had a chainsaw in my hands for 8 hrs per day 5 and sometimes 6 days per week, it got to the point where I didn't feel the chainsaw any longer. It was merely an extension of my arms. These were no light weight chainsaws either. I don't seem to get that feeling much anymore.
Yes them 50 year old McCulloch chainsaws will do that to ya...................