Lambda the Ultimate

Hi, I am just getting started with Lisp but am an experienced
programmer since earlier, with some cursory experience with
functional programming, and adept at picking up programming
languages.

I was wondering if it is ill-advised to learn two dialects
simultaneously, specifically Common Lisp and Scheme. I have some
books that relate to AI and interpreters where some use Scheme
and other CL and would like to be able to get work with books
from these two domains simultaneously.

So, bad idea or not?