Fundamentals are really useful and will elevate you to a very nice level.
However, in your pursuit of solid fundamentals, never let them box you in. Leave room for the creative and never allow yourself to get bloated by the “rules”. Agility is a must-have.
The fundamentals are great, but your ability to creatively improvise and break the rules is what will allow you to take advantage of disruptions and arbitrages in the market.
As they say, know the rules, so you know when to break them. Fundamentals lose their usefulness when they limit you from achieving your goals.