Correct usage requires learning the right abstractions, but fortunately these abstractions are shared across language communities and frameworks.
If you are doing any data processing work and you do not know about foundational functional concepts ie map/reduce then I would argue the code you write is less readable, overly focused on the idiosyncracies of how to do something rather than how entities and data are related to each other - their logic and structure.
The main optimization is to be correct and expressive of one's intention and purpose. If you need performance use Julia.