My very first overnight was when I was 14 in '76
My mom, dad little brother, and I took the train from Chicago to Los Angeles to go to Disneyland. I remember we had adjoining rooms, and bathroom in the room.
I spent most of my time up in the dome car. This was especially true at night. I love watching the landscape at dusk, and the lights of the small stations as we came upon them.
The most recent trip I took was from Dallas to Chicago a couple years ago. It was great.