dream sense?

[Daniel]

I have no common sense.

Last night I had a dream where my lack of common sense got in the way. Someone was talking to me, and made an offer I thought I had to refuse. He then POINTED OUT TO ME that he was aware of that reason but if I only spent two seconds THINKING about it, I'd realize it was no reason to refuse his offer.

He was right, and it was perfect common sense.

But wait: if I don't have common sense enought to realize something, and even in this dream it was evident. . . how did the character in my dream have common sense? He wasn't anyone I knew in real life. Just a stranger.

This isn't just a made up person with a quality I lack i.e. it's not like he's an olympic swimmer and I'm not, or a musician and I'm not. He had a quality it isn't possible for him to have; for this figment of my imagination to have such good common sense, he'd have to take that quality from me! But I don't have that quality!

My question is: how is this?