> and I think to myself this is absolutely nothing to do on the Internet. Which is bizarre to say.

Yeah it is, but I agree. It is more like a reflex move these days - the endless scroll, flicking from tab to tab, not doing much of anything. 

>I mean the majority of world wide knowledge is at your fingertips, but there is just nothing to do. 

Exactly. The operative part of the sentence "to do" - we are not made to be consumers only, yet we have been conditioned to be so. 

>I have also always noticed that on days where I am running ragged I find myself far less tired at the end of the day than the days when I have very little to do. It's weird how that works.

Also, the quality of sleep tends to be better after a busy day, at least for me.