Although the word “enthusiastisch” exists in German, the word “begeistert” is actually much more common. The German word “Geist” (m.) means either “ghost” or “spirit”, and thus one can link the word to mean “full of spirit”:

– “Ich bin ein begeisterter Hobbyfotograf.” – “I am an enthusiastic (passionate) hobby photographer.”
– “Ich bin von der Idee total begeistert.” – “I am totally enthusiastic (excited) about the idea.”

The word “Geist” has actually successfully crept into the English language as well. Although there aren’t very many German loan words in English, at least two including “Geist” can be found in any English dictionary: “Zeitgeist” (meaning “the spirit of the time”) and “Poltergeist” (meaning “ghost that knocks around”).

While we’re on the topic of creepy enthusiasm, if someone’s excitement levels are brought up to the notch of obsession, the German word is “besessen”, which can also mean “possessed”:

– “Er ist von der Idee besessen.” – “He’s obsessed with the idea.”
– “Er ist vom Teufel besessen.” – “He’s possessed by the devil.”