Some (extremely intelligent, I'm sure) motorist yelled out "Are you serious?" as he passed me today, of course not giving me a chance to answer:

Why, yes, I am serious.  I'm serious about burning off the cookies I ate at work today, staying healthy, and saving money by not buying gas.  The real question here, though, is are you serious?  Are you seriously yelling at me as you slide into the next lane to pass me, slide back into my lane (without a turn signal either time), speed, and turn your head to yell at me instead of looking ahead of you?  Seriously scary is about as close to serious as you'll get with that kind of driving.