Would you mind elaborating how you were able to do this in 5 years while getting an undergrad and masters too? Most PhD students can't do that. I didn't know this was even possible.
well, as an undergrad / masters student, i was lucky enough to join a productive lab in a hot field. i had my own project that i published as a first author (over a couple of years, of course) and a couple of side projects that gave me a second and middle author paper (in a much shorter timeframe). after i finished my masters i joined another productive lab where i got another second author. also, most postdocs / PhD students i've met in my field have put out many more papers than i have, so this might be field specific, too.
neurogirl is correct for the most part, it's just a combination of luck and circumstance. i had good advisors who put me in charge of my own project while letting me contribute to others, too. i also worked in fields where major discoveries were only recently recognized (think 2000s nobel prizes). sometimes this happens, but i can't say much else other than this.