What's the deal with staring? If something is fascinating, why not look?

Presumably there are situations where holding the gaze wouldn't help anything. The woman at the next table is uncomfortable about her huge wart and just wants to eat in peace. Staring would establish an unpleasant channel of communication. Fair enough.

But let's say you're walking down the street at night and there's a dude standing by a big truck packed with stuff, a garbage bag serving as a tarp to shield the contents from the drizzle; and he's got a small pile of stuff beside him on the sidewalk. Across the sidewalk from him is an upturned bicycle--missing a wheel. The dude is adjusting a small radio, tuning in some soul or R&B music which barely scratches its way in. In his hand is an open can of peanut butter. Don't you want to stare? Doesn't he seem to be asking for a stare, or, at least, knows he's in starable territory? Maybe an interesting conversation could even develop. The other option, to interrupt his lonely reverie with an entree to conversation--e.g., "What are you doing?"--that, certainly, would be a faux pas. But to stare? It is only natural, isn't it?