I mean, I'm sure we've all tried to look at the sun just to see what happens. I've never properly looked at it but I have made a few glances at it (especially when I was wearing sunglasses) when I was younger. It's a pretty stupid thing to do really because it's not at all good for you.
The danger is in the fact that your retina doesn't have nociceptors (sorry if misspell), which transmit the pain message to your brain in other part of your body. This mean you do not feel the damage the sun can do to your eyes before it's already too late. Because, well their's no warning..