Course three: "Prepare Data for Exploration."
This is where it stopped being theory. Choosing data types, understanding bias and credibility in your sources, and — the unglamorous heart of the job — organizing and cleaning before you analyze anything.
The lesson that stuck: most of the work happens before the interesting part. Sorting, filtering, checking where the data came from and whether you can trust it. It's the equivalent of prepping your ingredients before you cook — tedious, easy to skip, and the thing that quietly determines whether the final result is any good.
Also spent real time in spreadsheets and got a first proper look at SQL. Different territory for me, and I'll take it.
Three down. Halfway feeling.
