Just purchased Puerto Rico.
Out of the other board games I've purchased recently, including Pandemic, Ghost Stories, and Lord of the Rings: The Card Game, Puerto Rico seems more difficult to grasp, and I've been busting my brains out - watching youtube videos and re-reading the instruction manual - trying to get it.
The problem is I've never played a resource-based board game like Puerto Rico, so I don't have much of a point of reference. With Lord of the Rings Card game, I understood the fundamentals from my experience playing Magic the Gathering. I'll be studying from the ground up with Puerto Rico, and I'm hoping it'll end up being worth it.
It actually is pretty easy, but I also had trouble reading the instructions. It is because there is not really more to it than the roles, and only when you know them all you understand the game.
Maybe if you know the very essence of the roles you understand how the game works.
The Settler: Can take a quarry and place it on your field.
The Mayor: Can take colonists and place it on your quarrys/buildings to activate them.
The Builder: Allows you pay for a building that gives bonuses if they are activated and are worth points.
The Craftsman: Produces goods based on what quarrys are activated
The Trader: Allows you to sell a good for money
The Captain: Allows you to ship goods that give you points.
The Prospectors (sometimes not used): Gain money.
These are basically the essentials of the game, and you can see how they work with each other. So for example you first need to use The Craftsman to gain goods before you use The Captain or The Trader.
When everything clicks, the game is pretty easy to do as the rest of the mechanics are easy. It takes some time to read what the buildings do exactly, but you can just keep the rules as a reference for that.