It's common sense but a learning curve

As I keep reading and knowing more and more about usability, what I find, it's the matter of common sense. But no body uses it.

When we talk about usability, it's a nice subject, but when really working on something we usually forget about this part and work with our style. Because we are used to it.

example :
My boss asked me to find out address of one company, so I went to their website and then went to "Contact Us" page. I copied that link and sent to boss.
http://www.xyz.com/contactus.htm

brummmmmmmmmmmmmmmmmmmmmmmmmm

Where does it gone? where is my so called usability common sense.
I could have think that instead of this link, I would have copied that address from that page and directly forwarded to boss, as he is simply not interested in website and what he wanted was address.
Boss called me up and gave me first lesson about practical usability. Use Ability of common sense everywhere. :) I guess learning how to use common sense is learning usability.