Mark,
I would agree with you, and in fact I would extend that suggestion you made to include every conversation you have in everyday life.
You should never believe unconditionally everything you see or hear. Everybody has an agenda, (even you...even me!), and even if the person sounds 100% competent and educated, this confidence is often a facade.
People should always remain educated. For the rest of your life, you should be educating yourself. Not only will it help immeasurably in everyday life, it will also stave off the effects of the dreaded Alzheimer's disease (you can thank my BIO 110 teacher for that little tidbit).
-Britt