Physics and math. Physics because it helped me understand the ̶w̶o̶r̶l̶d̶ ̶a̶n̶d̶ ̶u̶n̶i̶v̶e̶r̶s̶e̶ Earth and the cosmos; math because it helped me understand physics.
@ElwoodBlues What so said is so very true. It's amazing how those abstract objects of pure mathematics, such as matrices, describe elements of the real world perfectly. I don't get why you said "the world and the universe" though. What's the difference?
