One of my favorite words is hubris, overweening pride, from Greek mythology. Tristan Louis has recently written an interesting history of Netscape and draws potential parallels to Google. It is well worth reading.
I will throw in my own bit of Netscape hubris. Back in 1998, when its world domination was in decline, Marshall Rose and I were writing our book on Internet email and we went to Netscape to talk to their email client product manager. He started off our session by asking us if we were familiar with the POP and SMTP protocols. Marshall and I just looked at each other and smiled: little did this clueless product manager know that Marshall’s name was on top of all those RFCs. That is hubris, and why Netscape eventually went nowhere in the email world. Of course, getting absorbed by AOL and whipped by Microsoft also helped move things along.