Realistically, you only need to memorize a few:

- rake test: run the entire test suite

- rails s: run the rails server

- rails c: opens up an IRB/pry session with your Rails app

- rails g migration: create a new migration

- rake db:migrate - Run new migrations

- rake db:create - create the DB the first time

- rake db:schema:load - generate the DB from schema.rb

- rake db:setup - generate a new database from migrations

- rake routes - Spit out the routes and path helpers

Don't ever use rails generate model/controller. It generates so much garbage that you likely won't need.

There are a bunch of other commands off of rake db:migrate but most aren't needing to be memorized. Our brains are only so large and dense and mine is particularly small, memorize what is important and memorize how to look up the rest.