Wait, what aged poorly about it? I don't know if you meant that but the disclaimer at the top says it did:

>>Warning: This document was written 15 years ago and is probably not relevant for today’s product managers. I present it here merely as an example of a useful training document.

I'm saying it's aged well! Despite the author's caveat, I think it's still accurate in a lot of ways.

Thanks for confirming. I skimmed it and I couldn't tell what he meant was no longer relevant; nothing seemed obsolete (in any obvious way to a non-PM like me). To his credit, it seems like he wrote the principles in a very general, abstract manner that didn't become dated with changing technology.