This reminds me a lot of how I feel about being in the lab:
The other problem with pretend work is that it often looks better than real work. When I’m writing or hacking I spend as much time just thinking as I do actually typing. Half the time I’m sitting drinking a cup of tea, or walking around the neighborhood. This is a critical phase– this is where ideas come from– and yet I’d feel guilty doing this in most offices, with everyone else looking busy.
It’s one of the primary reasons I’ve started doing a lot of work from home.