Most important subject to master
 

Hey guys,

In day to day, what are the most important subjects to master as soon as possible to be a proficient pilot ?
I intend to review my ATPL books/notes and I just want to start with the useful stuff first.

I am thinking about Performance and Air law.
Am I right/wrong ?

thanks a lot

Most of Operational procedures will be in your company's ops manual

...and specifically, those related to emergency procedures, your so-called DVA's (Drills of Vital Actions), Memory Items, Bold Print - whatever they're called at your company.

There is zero sense in going back to your ATPL books to review the basics of Class A airspace if you don't have down pat the procedures you need to do to evacuate an aircraft.

Meteorology!

Useful stuff?
Practice keeping that smile in place when you've woken up at 01:00z for a show at 02:30z, go at 04:00z and 1 of the pax has forgotten his passport...(Corporate jet ops).
Airline ops - just close the door, you're good to go. Although keeping cheery when the pax have imbibed too much alcohol and have decided to punch their way out. Cancel take off clearance, go back to stand, get the police. Call ops, refile the flight plan and lose all hope when the CTOT is now +2 hours....