Farewell, Neighbor (Whom I've Talked To Maybe Twice)

The neighbor across the street is moving.  Have seen some stirrings for a month now, but the "For Sale" sign makes it real.  That came up maybe a week ago.  The huge dumpster (like the one I threw my trash into last week) was on their driveway maybe a couple weeks ago.  And the moving truck was there when I woke up today.

I literally may have spoken ... no, come to think of it, I should accurately describe it as "interacted" with the members of the family that lives/lived there two times.  Once, when my niece was little, one kid who lives there, while he was being held by his father (the head of the household) offered her candy, and my niece freaked out.  The other time, the sons were playing catch (they had baseball uniforms on, so they may have come back from practice or a Game) and a baseball rolled to the edge of my driveway; I threw it back, poorly, to one of them.  And that's it.  I never had an issues with them.  They were the perfect, quiet neighbors who left me alone.

So I feel bad that I'm not saying goodbye to them as they're moving.  But, what would I say?  What kind of small talk could I come up with, especially since I made no talk with any of them while they were here?  And yet, when I came home from shopping earlier this afternoon and I saw the whole family running about, I thought about going there and saying hi.  But, I haven't.  And I probably won't.