You want to prove it to yourself at least once I think. Even if you only need the result, it’s nice to have at least once in your life a complete understanding

You want to prove it to yourself at least once I think. Even if you only need the result, it’s nice to have at least once in your life a complete understanding of what you’re using. I don’t remember many proofs that I did, but I’m happy to know the maths that I still remember really works.