If you're anything like me, your answers to the above questions will almost certainly be, "No, never" and "Hell yeah, just about every time".
And that's not surprising because I find I'm in a different mindset depending on which vehicle I choose to take out. Of course, I prefer to jump on the bike whenever possible but often I'll drive the car if the destination is that much further away that a bike ride would make the task unduly long. (That said, I'm not above routing a casual bike ride in a particular direction in order to run an errand 'on the way'.) And sometimes (to my discredit) I'll take the car on a shorter errand if I'm in a rush, despite the fact that there's probably not much time difference in it once you factor in parking.
Regardless of the type of errand or how much time I have to do it, when I go by car it's all about the task at hand. It's all business: get there, do whatever it is I have to do, go home. There's no sense of driving somewhere just for the heck of it.
And it's the exact reverse when I ride out on an errand. Usually I get to the destination and do the job, then it's, "Right, where can we go on the way home?" I almost always take the long way home. Down quiet back streets, exploring laneways and pathways, through parks, wherever the mood takes me. That's got to be one of the best things about cycling: fun is never far away.
This doesn't work in a car. Decades of car advertising can't be wrong: to truly enjoy driving you need the wind in your hair as you cruise the curves of a gorgeous mountain or coastal road. Or you need to be rolling down the kind of deserted city streets that you can only see at 6am on a Sunday morning. To put it bluntly, you need special conditions before you can truly enjoy driving. It happens—who hasn't experienced the joy of belting along a quiet country road on a sunny day? It just doesn't happen all that often. And it never happens when you're off to get a packet of screws from the hardware megamart.
Fun on a bike is found much more easily, more regularly, and more close to home. All you really need to do is jump on your bike and go.
In an old post on Copenhagenize Mikael argued that cycling isn't 'fun', it's transport. I agree entirely with his argument in that post, especially with how bad bike advocacy groups seem to be at marketing cycling as a normal day-to-day activity.
But I can't quite downplay fun in the same way. When it comes to bikes, transport and fun don't have to be mutually exclusive.