It's kind of funny how extremely similar English and German are, but you notice it only when you neither natively speak. Because of that doesn't the video even off to me sound.
It should be "I broke fast", not "I breakfasted", there's already a verb in there but people have forgotten, TBH "To have break fast" is quite questionable grammar. It's different in German, "Frühstück" means "early piece", an adjective-noun compound which then can be fed through the usual verbification rules.
From what I have gathered. In German you can just make up words, it it makes sense everyone will just go along with it.
There are a lot of words in English that could exist but if you made them someone would look at like you are stupid for thinking something that isn't a word is a word. You can't just make words.
Haha, I am a native German speaker, and I had a hard time following them without looking at the subtitles. But then, grammar is a fickle bitch in all languages.