I'd like to think I'm becoming Tom here, right down to the techs you mentioned. I also went through git, apache httpd, bash, and Ruby phases.

My philosophy is that if PHP keeps the lights on, I better really know what it is, where it's going, what are it's limitations, because it would be pretty scary not to.

Plus once you learn a language or a database well, the next one is easier. The trick is knowing when it's time for the next one.