Actually, I learned perfect pitch when I was 18 or 19 and became one of the best ones with it too. Realistically, absolute pitch is the better name for it, but it's not as 'zippy' as the label 'perfect pitch'.I practiced with a site called
www.prolobe.com and that kept all the stats and records of everyone. I had two usernames 'maestroanth' and curiousgeorge on that.
Since when I was at the university, I kept my ear in pristine shape with this site, and I ended up correcting a lot of other 'born-with' perfect pitcher's mistakes and some of them didn't like being humbled by a 'non-born-with-it' guy like me.

Furthermore, what I found amazing is that site sheds light on all the BS that goes on with perfect pitch talk by people that are ignorant on the subject. For example, the common story I hear is how so-and-so is so good with perfect pitch and they had it since birth and can spot the difference between A 440 and A 441, and then you put them under the prolobe test and they fail at it miserably. - And BTW, "It's always some fault with the computer" with them (when in reality they just need more practice). It's a humbling experience by many because it's really a lot harder than it looks......and because of this, I learned to not judge by word-of-mouth, but concrete examples by witnessing that person or cold-hard statistics.
This reminds me of a funny thing after watching a video on Messian in a composition class and the video bragged about his fine-tuned ear when dictating these bird-songs. I got in a class debate because I always hated these 'bird-songs' because in reality they're just dumb animals with no inherent musicality about them (IMO, dolphin songs would probably be the better pick, but I also realize Messaen didn't have gills ;P). Anywho, I brought the point that there was no way to check if Messaen was actually accurate when dictating these birdsongs. - We just took his word for it. The same thing is true for when I hear a word-of-mouth story of a 'perfect pitch' genius. - People usually just take their word for it and usually, around 90% of them aren't as correct as we might think.