I had a somewhat similar experience with the Fourier/Laplace transforms, which I learned as formal tools for solving differential equations. It wasn’t until three years later that I learned what they meant — how they represented frequency, growth, and decay — how they turned the signal inside-out and showed it to you from an entirely new perspective. That was one of the most exciting moments of my life. I’m still in love with the Fourier transform; I still consider it to be one of the most fascinating intellectual constructs I know
Source: worrydream.com
