Back in 2000 I was on a Virgin 747 flight out of LGW where there was some interesting turbulence just after take-off. I'd had up-and-down stuff before, but this had some fun side-to-side motions as well, and overhead bins were popping open. I was just thinking 'wow, this is bumpy', the people across the aisle from me were praying. We were quite far back on that occasion, I suspect that it's worse back there than over the wing box.