I remember being on a Virgin 747 out of LGW a few years back. It wasn't a full flight and we had some interesting turbulence on the climb out, with lurches in all directions, overhead bins popping open and much shaking. The people across the aisle were praying, I was just thinking "Wow! Good one".
Last time out we were sitting in the center block of row 56 on a 747 and on the ground the wings were visible through the windows. I pointed out to my son that once we were in the air, he wouldn't be able to see the wings anymore because they'd be bent upwards out of view. Then I had to explain about the wings being full of fuel and hanging down from the fuselage, but once airborne, the fuselage would be hanging from the wings.
If you want to see how much some of these aircraft can take, there was China Airlines 006 that lost control and got really close to Mach 1 with bits being ripped off and yet landed safely. Aloha 243 lost a lot of fuselage and still landed safely, United 811 had a lump ripped out of the side and landed safely. The recent BA038 777 landed well enough that some passengers thought it was just a bit of a hard landing and hadn't realised it had crashed. They build them tough.