You don't have to be a dick about it. Just actually try to talk to them about music, and if they don't know anything about what you're talking about, they'll probably give you a look that could curdle milk.

Right after the Beatles arrived and all those other bands followed my taste developed quickly............

List the base genres, just give examples. Punk, Rock, Metal, Blues, Jazz, Hip Hop, etc, it'll usually go off from there.

Just tell them you listen to Metal, and if you say what kind of Metal you prefer , tell them what Doom Metal basically is in a sentence or two, I don't think it would be that difficult.

You can still just give examples of things or genres you've listened to. At least start with the base genres, there''s a lot less of them to list than sub genres :P. Then people will usually ask about one of the base genres you like. Just explain yourself, just tell that your examples are not fully representative, but just to give an idea. If they don't know about a band, you can always give a short explenation, just to give them an idea.

I have a friend that listens to a lot of k-pop/j-pop and electronic music, which he knows I'm not a fan of, but I don't flat out say what I really think about some of those artists. At least we found one band in common: Maximum the Hormone.

That's what I mean, I know you listen to a ****load of music, and even then you barely know every genre that exists.
The thing is, I mostly hear this phrase from people who don't know much about music. People who barely ever even listen to albums. They just don't know.
Either that or..someone pretentious, so you're sort of right. Once I even got someone that whined about genre labelling and how genres were pointless...I guess it's a defence mechanism for calling a pretentious person out on this..*sigh*.

I've always had a very diverse taste in music. When I was a kid I liked rock (esp. the industrial stuff that was coming out in the mid/late 90s), metal, and a little bit of hip-hop kind of stuff (Eminem's Slim Shady LP was my first CD), and quite a bit of top 40 type stuff as well as whatever my parents listened to (almost always classic rock). Grew up to appreciate alternative and some of the heavier stuff, got way into hip-hop (especially golden age and Ninja Tune type stuff), and honestly I can't really come up with a style that I think is best.

Punk is great, metal is great, electronic stuff is great, and there's really never a time where I've said that I was content with the amount of music I've listened to because there's so much I haven't heard. The more you hear, the more you love it. Sometimes I like to listen to Pandora or search random stuff on last.fm just to find something I've never heard before and I'm never disappointed.

24 years and counting.

When did you discover your genre of choice?
Generally, my favored genre is metal (of many varieties) and it's been this way since 2010. I discovered my interest simply by listening to a lot of music but my ears followed the route to metal.
Internet radio and YouTube has been a major catalyst as an important note.

When did you discover your favourite band/artist?
Like many here, favorites is a concept that's too black and white. I will say a notable artist, Norther, was discovered first through Pandora as I was listening to my Dimmu Borgir radio station.

When did you last discover a new genre?
None of the genres I've listened to has been profoundly new, but I didn't realize the name of the music I listened to was symphonic metal until 2010. Does that count? Nor did I dive deep into it until that year either.

Would you consider your tastes set in stone?
It's fairly rigid. I still haven't been big into jazz, classical, r & b, pop, rap, country, etc. that's outside of my umbrella.
Set in stone I can't say. I reckon few people are that 2 dimensional.

Overall, how long have you held your current tastes?
2010-Present. I could travel back in time show the exact same music to my old self and I bet he would enjoy it. Before that.. Would be interesting because I listened to the local radio station and MTV as my influence.

not long imma say about 2 weeks

Well, it all started with this:

http://www.stereogum.com/files/2009/...one_decade.jpg

This issue got me into all the great records:
Wilco - Yankee Hotel Foxtrot
Radiohead - Kid A (and all Radiohead for that matter)
Yeah Yeah Yeahs - Fever To Tell
My Morning Jacket - Z
LCD Soundsystem - Sound Of Silver

And so many more. So honestly my whole perception of music at the time was flipped on its side. I was hearing all these new sounds at once and my then current taste of music evolved within a year or so.