GamerGate destroyed my confidence that the mainstream media tended to get things right and pick the right side. That doesn't mean it is always wrong, but it is not always right either.

The supreme court ending any ballot recount and investigation into corruption in Florida during the 2000 presidential election. Gore won that one by a hair and Bush only took office because Florida threw out ballots to steal the election and the supreme court rubber stamped it. Any and all optimism I had for democracy in the US died that day and it's weird to me that we just sort of shrugged and ignored it.

Does it have to be an event in our lifetime (and not a historical event we learned about)?

An oil change place completely draining my car out of oil and not putting a single drop in. This eventually caused my car to overheat and the engine ended up blowing up. After this I've come to realize that there are some truly evil people who will try to sabotage your life without even knowing a single thing about you. Pretty much don't blindly trust anybody even authoritative professionals like doctors, mechanics, law enforcement, etc..

The death of my father. Before that i was always busy taking care of someone else. Now i'm much more thinking of what i need and want from life.

Its interesting how much of the comments focus on negativity.

For me it was mediation that solved a lot of my anxiety and changed my view of the world, along with a bit of stoic philosophy. Thats not really an event by itself but it was an event for me to discover mindfulness.