If you think you're going to memorize that entire textbook in a week, you've got another thing coming. Use the concept of spaced repetition to learn things forever. It's the idea of reviewing terms, definitions, or formulas regularly so you'll remember them in the long term, not just for the next 24 hours. It's pretty simple: If you understand the concept well, you'll review it further in the future and if you don't understand it, you'll review it sooner.
There are a handful of browser add-ons and apps that can remind you to review material using special spaced repetition algorithms. You can create flashcards using Anki (free, web), highlight ideas from any website with Hibou (free, Chrome extension), learn new languages with Readlang (free, Chrome extension and web). You can even find subject-specific apps like Firecracker for med and pre-med students or Brainscape (free, iOS), which offers a variety of pre-packaged subjects.