Well, I had never heard of this day before, so you can guess I'm not from US (but from Europe).
Even in school I've never been taught he was any kind of hero or even someone "good". Lessons could be summed up as : he "discovered" the new world (insert vikings stories here), then what he did was basically enslaving and mass killing people (sometimes "accidentally" with diseases they brought), and had extremely brutal ways to deal with the "savages" he found he could exploit for gold and other riches.
And now I learn that some countries have a
national holiday in his honor ? With Spain even using this date as Fiesta Nacional ? I'm really confused here.
And yes, I learned it from
http://www.theoatmeal.com/comics/columbus_day, but no, I never use theoatmeal as a "real" source of information, he really uses way too much unverified/biased information (don't take anything you read on this as fact)... but what's more than sure is that there is enough information on Columbus to know he was definitely not someone any country should worship.
"Fun" thing is that in the US, you also have a national holiday celebrating the end of civil war, which resulted in the abolition of slavery, while on Columbus day you're basically worshiping the pioneer of mass slavery between your country and Europe. This feels crazy.