In reponse to the OP's question, yes two people at different times on different Amtrak trains but with a twist and a co-incidence too.
First we met our great friend Milton on the Southwest Chief heading north from LAX. We were on our way to Kansas City, he on his way home to Syrcuse via Chicago.
As often happens on an Amtrak train we met after being seated together for a meal where the frequent question arose "What do you do?". We gave our version, then he said "I'm a rocket scientist". We certainly don't meet many of them on a daily basis, and in fact Milton was and is the only one we have ever met. On first thoughts we thought he's mildly joking with us as he said it with a smile, he's a shy man and it was the first non reserved thing he'd done, smile.
It turns out after years of asking him questions we understand he worked through much of the US/NASA space program, starting with the Atlas rockets through to the Shuttle. He also turns out to be a very nice man too and a great human being with a sense of humour, aren't we lucky.
A few years later the second life long friend we met was on the Sunset Limited heading from LAX to New Orleans, this time we were travelling with Milton as far as San Antonio where we remained on the Sunset, he continued on to Chicago with the Texas Eagle. Milton and I went to the diner together but at the time Rosie wasn't hungry. We joined a lone man sitting at the diner, he gave us a pleasant smile, said hello and continued eating. Milton and I talked, we included the man sitting opposite when we could until he had mentioned a few things that appeared unusual, connected but not connected. I also noticed some of the other diners glancing across to our table (did they know we were eating with a rocket scientist?).
It turns out our dining companion is an actor, and if you watch movies or have Netflix you would know him. Neither Milton or I hardly watch either. So at one point I blurted out "should I know you, are you famous?" He laughed and said he was currently in a Netflix series and he had done a bit of acting but was not a high profile actor. He also said he enjoyed talking with people who didn't know who he was, in our ignorance we took him just for the person who was in front of us.
He's a very nice man ideed, also interesting too. We enjoyed his company every meal time thereafter and often at longer station stops through to New Orleans. His name is Matthew Modine and Stranger Things was his then current job.
Rosie joined us before our meal was over and was introduced to Mr Modine. Later Rosie and I went back to our roomette and sat with our door open so we could catch Milton on his way back to his car, he remained to have an extra hot drink.
In the same car across the passage from our roomette was a lady travelling alone, we'd say hello, how are you but as she appeared to want her own space left it at that.
While waiting for Milton we spoke with Dorothy as she too had her door open just sitting. She was full of life and laughed easily, a nice person to spend some time with.
When Milton came past we introduced them, chatted with Milton for a few minutes and said goodnight to Dorothy.
Next day Dorothy and a second lady were sitting opposite Mr Modine for breakfast, by this time the whole train knew he was onboard. We said good morning to them all and sat at the both across the aisle from the 3 of them, that was the meal pattern for the rest of the journey the 5 of us sitting together on 2 tables.
Dorothy was in the Pentagon on 9/11, she had an appointment with her boss that day but was asked to delay it for 30 minutes. Her boss was killed and Dorothy survived, it made a big mark on her.
She's a special lady and we stay in regular contact.
We have met others too, most we are in infrequent contact with, not very regularly. We've also met the lovely Jeb and Chelsea who are part of the AU forum, and then there's Bob Dylan from here, a very fine man indeed.
The co-incidence was Milton and Dorothy were on the same train in the same place at the same time, but we didn't really know Dorothy while Milton was onboard, they met but only as strangers. What a small world.