Why do some people think Irish people can't have dark hair and brown eyes?

It’s just a stereotype. They’ve probably just never truly thought it through.
It happens to the best of us.

The same reason someone was surprised I am Jewish because I have blue eyes and medium brown hair. Ignorance. Not to be confused with stupidity, they just are unaware.

Also you’re not fully Irish haha I joke. But seriously, it’s fine, I have green hair and purple eyes and people find that weird as well so ignore them. I’ll shut up now.

Just to follow up on @Luiveton‘s joke. Dark features tend to dominate. The irish usually do have fair skin, so I am assuming your olive skin does not come from your Irish side? Dark hair is not uncommon for the Irish though.

He never heard of “black Irish,” I guess. http://en.wikipedia.org/wiki/Black_Irish

He is either ignorant and doesn’t realize it or is flirting with you and it is a joke.

If he seems interesting enough, or there is some one interesting close by, choose the later. Humor always gets extra props.

My guess is also stereotype. As such, allow me to be a hypocrite; someone can’t believe that a person of Mexican root can’t have dark hair? Erm.

It’s like if I said every Scandinavian person has either blond or red hair. Just ain’t the truth.

@RockerChick14 I can can only imagine that you can be model quality with those unique features as you describe with the dark hair, brown eyes and olive skin. You may see my compliment as stereotyping because I don’t know you.
That’s simply the problem with stereotyping that was created via media, movies ext. If you see an Irish chick you expect blond hair and blue eyes because we see it in the movies and media. My grandfather on my fathers side is Dutch and on my mother side is Irish, I don’t walk around with clogs. Or dress green on saint Paddy’s day. I believe when people stereotype someone is because they are either very arrogant and miss informed and have no knowledge about any culture or any person.

You all should read @answerjill‘s link. The stereotype is there because there were some statistics to support it. Down near the bottom it says back in the 40’s less than 1% of the Irish had pure brown eyes genetically. Something like over 40% were pure blue. The people with darker skin are genetically linked to the Iberian Peninsula and other areas with darker skin. If you are an American, most of the Irish that came over 100 years ago were pale, many with freckles, brown hair and blue eyes. It is ignorance to think everyone from Ireland is pale, blue eyed, and fair haired, but the stereotype is not that hard to undertstand.