It wasn't 2 full years, but... certainly, multiple stints of 8 hour sets for weeks on end - it's basically a full time job. Other 'factors of the time'. They

It wasn't 2 full years, but... certainly, multiple stints of 8 hour sets for weeks on end - it's basically a full time job. Other 'factors of the time'. They wanted to play rock and roll. There just wasn't THAT MUCH of it. In 1961... there were a few years of the genre, several albums by their heroes, but... it's not enough to play and attract people in bars for weeks on end. There were other factors too, but that constraint was one, that helped push them to expand a bit beyond just 'rock' stuff (some earlier standards, etc) to help differentiate themselves from other bands (and eventually self-composing as well). By coming back from... IIRC, their second or third Hamburg stint, they had somewhere around 800 hours of playing together as a band. That just wasn't a thing (yet). I mean - not even most of their heroes/idols didn't have that much stage time as a single unit. The "self-contained rock band" really wasn't a "thing" yet. I've been in bands, and we were never even in a position where we'd be able to play 6-7 hrs a night for weeks on end. I'm sure no one would have wanted to anyway (like you say).