In all honesty, I can't say I "celebrate" many holidays, in the sense of doing anything to honor that day's theme specifically.Perhaps it's a reflection on my character, or lack thereof, but most holidays to me end up being about spending time with friends & family, bbq'ing, heading to somewhere fun, etc., rather than being about, say, presidents or independence from England.
Given the times, and maybe the fact that I'm getting older,some holidays, such as Memorial Day or Veterans day, elicit more thought and emotional response these days. MLK day is, IMO, worthy of a little thought as well. I know it's not popular among those who hate political correctness (and I count myself as hating PCness too), but I think you do yourself a disservice if your view of MLK day is merely a reaction to political correctness.