While we have our off days, where we are both so tired that our greatest tool for staying awake is completely pissing the other off with ridiculous arguments, usually our conversation is stimulating (in a non-rage-inducing way) and entertaining. Thus, on days when we don't drive together, everything seems tinted a shade grayer, my temper flares more easily, and the drive home is much more of a chore.
This past week due to absences, we only drove together twice, and I feel the poorer for it. Sure, my drive time is shorter and I get home a bit sooner, but without the energetic conversation to start my day and the commiseration on the way home, I feel a bit empty.
I've spent a good portion of my life driving alone, and I don't care for it. I suppose that I need to take these days when I am forced to drive without my carpool buddy to grow a greater appreciation for him. I can honestly say that the experience has changed my life for the better.