drupal like all custom made software requires some time to learn it. It is very good from when I used it.
Very easy if you know the PHP funda.. Just refer drupal.org site and watch the video tutorial from youtube..
Joomla is easy to learn, while Drupal need a steep learning curve but knowing Drupal can be more powerful to building large site compare to Joomla.
Practice makes men perfect. Things are difficult until you don't try. I have been working with joomla it seemed hard when started first time after that i understood everything now seems so easy..
IMO depending on what is your target. if you are looking to build standard 5 pages site, Drupal and Joomla is pretty much has the same learning curve just different approaches. But in other hand if your target is to build super complex site, if you are not savvy with php objects way of coding, Joomla will be a nightmare for you while as of Drupal, it has steep learning curve to understand what is "Drupal way" to do things but the code it self is pretty straight forward if you understand php.