I do see that you can go a long way with relational databases just using experience. However, they do have a formalised mathematical basis and I think you dism

I do see that you can go a long way with relational databases just using experience. However, they do have a formalised mathematical basis and I think you dismiss it too quickly. If you do spend the time to learn the maths then it will push your abilities that little bit further. You'll also likely find it quite easy to pick up given that you already understand the field well.