Flying from San Francisco to Tokyo in 1987 we encountered some turbulence.
It wasn’t even all that bad, but I was seated in the tail of a United L1011.
Looking forward, I could watch the restrooms, overhead bins and other parts of the plane moving in different directions.
I was sure the structure was coming apart when someone commented that “this must be one of those old Panam Lockheed L1011s that United acquired.”
My first flight on a commercial airline was flying from St. Louis to Philadelphia for Christmas 1969. I was a freshman at college and starting mechanical engineering school. I could not believe how much the wings flapped up and down on that aircraft. I was sure that they were going to break off. After a few courses of structures, statics, dynamics, strength of materials, etc, I had a much better understanding of why wings were flexible. But I still remember being really unnerved by that sight!