My mid 20s were when I hit a major mental breaking point. If I hadn't had a good support network of friends close to me and family I could turn to...
26 is old enough to feel like you've lost everything and that nothing will ever be good again. He left a good career for his morals and lost all hope of employment from it.
Thiel has 2 real fears and he's been pretty consistently worrying about them.
A proletariat uprising would be apocalyptic in his view AND he would undoubtedly get the Mao special if one happened.
There's 0 chance of one because Americans are way too divided but this killing is the biggest source of existential dread for him and he's probably been waking up with nightmares about it.
Couldn't happen to a nicer guy