My life as a Drupal developer was forever changed when I learned to use X-Debug with PHP Storm. Suddenly the mystery of all those variables and functions was accessible and I had a way to figure out, "WHY ISN'T THIS WORKING!!!", and depend less on Stack Exchange solutions and more on writing my own solutions. The real revelation wasn't that I could debug PHP code, but that I could think about solving the mystery of why something wasn't working in a new way.
Whether it is figuring out how to get Drush working with MAMP, eliminating all those JS console errors, or trying to figure out if the bug is in core, the theme, or a module, the solution is always the same. Use your detective skills and the tools available to you to eliminate all the possible points of failure and don't forget to ask for help. Sometimes just seeing how someone else goes about unraveling the mystery can change your perspective.