Wartime

In fact, Ströbele has went through some stormy times.
He was a lawyer to RAF members, he's experienced the turnarund, in the recent years he dealth a lot with the topic of "secret services taking too many rights for themselves", even visited Snowden in Russia - and, overall, he was a founding member of the West German Green party, but he didn't come from any of the ecological topics that so many still create dogmas with today. He's more rooted in the political background music of "make something different than what we already know and disapprove of". (The part of the Greens that is no longer today.)

And, indeed, he was pretty down-to-Earth as a person and known for this attitude in his election district. - The only Green party member who always received a direct mandate every term in his election district in Berlin for as long as he ran for it.

Too bad now that he died... But it was foreseeable.
Aged 83 you don't need to keep yourself in dreamy illusions how long it might still last.
On top, he also was said to have had to fight with cancer more than once already.