The bike
Everyone has their COVID baby (dog, human, whatever) and mine was a 1983 Schwinn High Sierra. I bought it specifically to learn more about rebuilding a bike from the ball-bearings up. Found a dude down in south bay selling it for his elderly neighbor. I think it was $200 or $250? The soundtrack was Fiona Apple's Fetch the Bolt Cutters along with Pearl Jam's Gigaton. With those two albums on repeat, I spent most of my evenings after work learning the tools and techniques to pull every little part off of the frame to get a thorough wash or replace.
First approach was to try and keep it mostly stock. If I remember, the bottom bracket was trashed. The headset was bad but I wanted to replace anyway. The bearings in the wheels came out nice after some deep clean and regreasing. I kept the old tires for a time. The cockpit was almost entirely salvageable, except the grips had that old sticky rubber feeling.
It was a really fun platform to play around with so I went through all kinds of iterations of handlebars and riding types. Took it once on a bike camping trip through Henry Coe which was kind of a nightmare.