How to reset my password if I forgot it? I forgot the admin user pass for my site. Then I followed the process to recover my password. I get an email with a link (available for 24hs) which allows me to login in my site. I go to 'user/1/edit' to create a new password, but the old one is a REQUIRED field. This is wrong, I forgot my password, then I can't fill this field.

Am I missing something here??
While you can change admin password either by drush or by running mysql query if you have access to database if you do not have direct access to your mysql server, install devel and wrap the mysql query with drupal query wrapper functions and run it at /devel/php page.

You may want to consider having nocurrent_password module which removes the current password field and you can directly update your passwords, NOTE: this behaviour will be same for other users as well.