Someone explain this

Welcome to English language

*checks roll call* Uhm... Say-ann? We got a Say-ann here?

I thought it was pronounced 'seen' when I was little.

Irish language. Sean is Irish.

I swear it should be pronounced "scene"

It's gaelic

I know a guy who actually pronounces it seen. It gets confusing though sometimes because eeryone else is shawn

Ok, I just wrote this in the comments of another post yesterday, weird......my name is Sean and it IS pronounced Shawn and I do have people pronounce it See-Ann and Seen.
http://m.funsubstance.com/fun/205434/i-guess-some-peoples-names-are-more-exotic-than-mine/?last_comment=1075345

One time when my girlfriend was in kindergarten she got to do roll call and someone was named Sean and she kept saying "Say-ann" over and over again and it was wonderful

How else would you pronounce it? "Saiyan"?

Here's the thing; In linguistics, an "S" sound softened (palatalised) is pronounced as "SH". Assuming the letter "E" in "Sean" is pronounced "EE", the "S" can be pronounced as "SH", because the "EE" sounds softens "S". Then, if the "E" is pronounced "EE", and the "A" is pronounced "AH", then the "EA" in "Sean" is pronounced "eeyah". Thus, we have "See-yahn", but because the "S" is softened, it is pronounced "Shee-yahn", and the "EE" sound is pronounced so quickly as to be unnoticed; or, it is pronounced just enough to turn "S" into "SH" by palatalising (softening) it.

Its actually Irish for the name John

Why does the name Sean Bean not rhyme? Why god, why?

Okay, so my brothers name is Sean and everytime I get mad at him I call him seen and he gets pissed. But it's spelled Sean because it's Celtic. It's an Irish thing.