In The Sims 4, you can learn the first four levels of a Skill from the first volume, though you must reread the book to do so.

Skills may be learned from Skill Books, read at the Library or purchased from the computer for use at home. Each level your Sim gains in these Skills will improve their performance and unlock new abilities. Tell a joke, and wham - you've got the Humor Skill at level 1. If your Sim talks to others a lot, Charisma will gradually develop. This will help you to utilize all skills that could be helpful to you. They reflect how good a Sim is at doing some activity. Skills in The Sims 4 unlock the moment your Sim performs an interaction related to them. You can find more details about them on their respective pages and in the alphabetized list below! What Are Skills? The Snowy Escape Expansion Pack adds three new skills, all related to Winter sports and mountains: Rock Climbing, Skiing, and Snowboarding. The Sims 4 Skills Skills List and Ideal Emotions Strategies Snowy Escape Additions!