Alan Kay says the computer revolution hasn't happened. Here's a talk he gave at OOPLSA in 1997. He has gems such as "I made up the term object-oriented, and I can tell you I did not have C++ in mind."
In Mastering Perl I emphasize that people should pay attention to the masters in their discipline. If you only work in Perl, that doesn't mean that you'd limit yourself to just the big names in Perl. The language is merely an expression of ideas. A different language will express them in another way, often giving you more insight.
I also note in my Mastering Perl classes that I hope we are in the dark ages of computer programming. If we're close to the pinnacle, we're all in trouble. I sure hope the revolution hasn't happened. It has to get better or we are all doomed.