I spent most of my time getting into its vision and philosophy, trying to distance from the object-oriented mindset that my previous studies and experiences had consolidated.
Which would be somewhat off the mark in Erlang. Control flow and common interfaces are frequently expressed via adapters written using polymorphic pattern matching functions. Processes are message-passing, isolated units of work. Modules and OTP applications are encapsulation, etc.
The functional aspects aren't as important as the pattern matching on data types.