Ah, no, I don't want to be a tuner, but I would like to have a more intuitive sense for intervals so I can, I don't know, mess around and actually sing things properly and be like one of those cool musician types who's like, "Yeah, let's transpose that to A Lydian", etc. etc.
Actually, the problem came up when I was trying to learn guitar and jazz. I'm working with Mark Levine's "Jazz Theory Book" and the very first page is getting an intuitive feel for intervals. I play the examples, try to sing them, listen to the songs, but every day I have to start all over again because I just cannot remember what they sound like. I'm not sure if this is normal or if it's a personal problem. As for the guitar, I can't tune it by matching strings because I can't tell if they're sounding different notes (and if so whether they're lower or higher); I have to use an electronic tuner.
I've been doing ear training exercises on good-ear.com lately, just the "beginner" section, and sometimes I think I'm getting better but I always end up with around an 85% accuracy rate. And that is trying pretty hard too, playing the intervals multiple times and slowly (for some reason I find it easier to hear intervals played on the violin). But to be fair, I've only been doing this for a few days. If it's just a matter of work you have to put in, I can do it with no problem - it's just that everybody acts like it comes naturally so I don't know if there's something wrong with me.