"Matěj, why don't girls want you?"
Translation:Matěji, proč tě holky nechtějí?
https://forum.duolingo.com/comment/31466920/Ordering-the-Czech-clitics-Introduction-2019-04-18 I hear you, I felt the same until I read this. Then it all finally made sense and now I love the second position.
But, in the example given "Mateji, proc holky tebe nechteji", tebe is NOT in the clitic position. But, not being a native speaker, I'm just not sure why it's placement isn't correct. How it's stressed seems to be the answer. But that's a subtlety of the language that is a complicated for a beginner. But, I guess that's why we're doing this course!