[coffeemaniac]

That's not true, by learning what it feels like to sing different notes it's absolutely possible to "learn" perfect pitch. There are some individuals of course who are born with a very acute sensitivity from a very young age (which is spooky) but there are also people who learn it later.

If you can imagine learning to recognize and accurately sing just one particular note (say, middle C). Then if you develop amazing "relative" pitch it's basically the same thing. Training more still will enable you to hear very subtle differences in tuning, but it has to be a standard part of your training.