The UK spent decades convincing everyone that all bad decisions are made by the EU and all good decisions are made by Westminster. That’s the first mistake.
If the UK had properly educated its citizens about what the EU actually was and did, no remain campaign would’ve been necessary whatsoever. But it was politically convenient to have a scapegoat.
And let’s be honest, remain aka “remoaners” had a ton of arguments all the time. But brexiteers just wanted to enter the magical land where the UK still mattered and they’d eat their cake and have it still.
Just go ahead with the tutorial. Kotlin is basically identical to Java with only tiny changes, and you can just look those up whenever you see something new.