I take Vonnegut's statement as a lesson in serendipity. Sure, life is as convienent as is, but its the small chance encounters and observations that make up a fulfilling day.
I'm someone who could just fart around, due in large part to being born at the upper end of the wealth and opportunity lottery, then taking advantage of it. Most people simply just don't get the same chance. We might want to think about other goals, like making the world a better place to fart around for those who weren't as lucky?
Even sex seems like a loftier goal than just farting around.
So he "stores" his envelopes over at the news stand in order to have the experience of going to and buying and returning with the envelope. As a teller of human tales, this isn't yak shaving, it's more like reading random repos. It isn't farting around for him, it's training his core economic advantage. If I kept my envelopes down at Walgreens and drove there for each one, it would be farting around.
What a sad worldview this is.
The guy was in Dresden, Germany when it was destroyed by firebombing in WW2. It may be sad compared to some views but after what he saw, it's remarkably positive.