I wrote about this in detail on the AWS Training & Certification Blog.
The short version: I started from my dad's couch in 2019 after my music career fell apart, earned my first certification in a month, and worked up to all 12 over six years — eventually receiving the AWS golden jacket awarded to those who complete the full set.
The five strategies that made the biggest difference: strategic use of AWS Skill Builder resources, turning each cert into a hands-on mini project, a 30-day sprint structure using spaced repetition (the 2357 method), protecting study time ruthlessly, and building a cloud community instead of going it alone.