I remember once encountering a savage bit of turbulance on an SQ jumbo en-route from Manchester to Changi back in 1999. I travel a lot and this WAS savage, believe me.
I was with a mate who'd never flown before and was a bit nervy about it before boarding. Anyway, my abiding memory of that flight was a load of young students screaming their lungs out and me turning to my pal imagining him to be terrified. He was laughing away loving every minute!
The skipper was a cheeky Indian chap who piped up after we'd cleared the weather with "sorry about those little bumps back there." A master of the understatement.