Senior-year undergrad but only now fully internalized what second derivative means and SE is trying to tell us and it feels SOO GOOD!!! sorry if the post is irrelevant for the sub but just want to share this orgasmic feeling of finally understanding something. Whenever we'd solve differential equations and discuss exponential and oscillatory and all those behaviors of wavefunctions, I'd be like "yeah sure makes sense" but there's always this itch in the back of my mind telling me i have not *really* understood it but i am not bothered either. right now, I was preparing for my finals and was studying potential and bound state problems through JWKB approximaton, and i was deriving everything from scratch, and realized I dont understand why SE has double derivative, and then realized I dont really understand what second derivative means. And, now after spending over an hour learning it, it felt SOOO good that everything started clicking and the whole of SE makes so much more sense now.…