I was writing a lot of Perl while I was in school. Yes, part of the reason that I picked up Python quickly was that I was a more experienced programmer. Still, since I learned Python, I've had to occasionally go back to Perl for weeks or months at a time to work on old code and it's never gotten as comfortable as Python. If the ease of learning a language was only (or even mostly) dependent on the experience of the programmer (as you seem to suggest), I should have been able to go back to Perl and be even more proficient in it than I was in Python since I then had even more experience.
I love Lisp, but every time I've attempted to use it for something non-trivial, I hit a wall usually involving libraries and cross-platform issues. Eg, last time I attempted to write a blogging engine in Lisp, I never managed to get an ORM library, a webserver, and a templating library all installed and running at the same time in the same lisp interpreter. One or the other seemed to have issues with SBCL, Clisp, or Allegro that I wasn't able to debug. But I keep trying once a year or so and each time I make it a little farther. So maybe next time. In the meantime, I do write a lot of emacs lisp and it makes me happy.