I once managed to trip over a 5 cm metal ledge that I only noticed when I kicked into it while walking into a parking garage.

I fell over, fell on a knee that was just healed after another less stupid fall and scraped both hands badly too when I tried to break my fall.

So stupid!

Oh and it was after a concert and there were a lot of people present just watching me get up, crying in pain.

So it was my most embarrassing one too.