Why did you cease being a solipsist after having such an experience?
It was pretty easy, once I thought about it a little. First of all, within the context of the dream I had, there had been a way to test whether I was in the dream- I just tried really hard to open my eyes. Granted, it wasn't a very good test. It's not always easy to wake yourself from a dream, and there's not much one can try if this fails, but it had worked.
Ultimately, I just told myself how useless solipsism is in a real-world context. We might all be trapped in the matrix, but if there's a way to test whether we're in the matrix and get out, then there...
This is a kind of "X files" thread.
Post experiences which spooked you, which made you doubt reality, mathematical or physical laws, your sanity, memory or perception. The more improbable the better, but no second-hand legends please, share only what you personally experienced. If you had the event later explained rationally please use rot13 to avoid spoilers.