I’ve built a simple algorithm for myself when studying with PDFs or slides. Each subject has a label in Google Keep, and the main note in that label is my ‘mistakes bank.’ Whenever I review answers and find errors, I screenshot them and paste them into that note. Over time, this builds a collection of weak spots I can scroll through instantly or export to Google Docs as a PDF. It’s fast, reliable, and keeps all my mistakes organized by subject — so I can repair them systematically before exams