In all seriousness, why can’t I smile?

Recently, a professor of mine warned the class about the dangers of putting anything "cute" in e-mails to professors, resumes or anything formal. I understand the necessities of formality and seriousness, but I still have trouble with the fact that I will get penalized for putting a small emoticon next to my name at the end of an e-mail to my adviser, professor or employer.

The main problem I find is simply this: why can’t I be cheerful? Everywhere I go, I find multitudes of angry self-absorption and people that will cut your throat if you so much as smile at them. Is that the same world as this so-called serious one that I "have" to interact with?

Why can’t I be kind and be happy? Why can’t I smile at my professor even when we’re supposed to be formal? And perhaps most of all, why would someone get angry at a perfectly crafted essay-like e-mail that features not only perfect grammar, but well thought-out sentences and interesting ideas just because of some friendly gesture?

Maybe in the business world, there is no such thing as kindness, no little acts of nicety. Why would anyone want to live in such a dismal place at all? "Oh I’m sorry, sir. We would have hired you and all because of your excellence in school and extra-curricular activities, but that colon and parenthesis in there made us reconsider.." I apologize. Next time I just won’t be so pleasant.

No, I could never do that! : )