Nadine- I really like your honesty here! I think you are wrestling with something many do not wish to voice. We accept the math, but it seems very weird that nature would work this way. That is why experimentation is critical in the scientific process.

So, never, ever accept ideas simply because anyone says so.
Challenge yourself to think through, like a detective, and find where the logic goes awry.
In this case, think about what was known about nature that led to the question of simultaneity:
1) That light is a constant speed and
2) that it is impossible to tell if one is traveling at constant velocity or not.
Are you convinced of these? Why? Why not? Given these, does the train example follow?

Here is a question for you or anyone else: Do we cling to the math because the nature of reality outside the cloud of our everyday experience is so strange?

Why do you say, “In truth they are both moving towards each other at a constant velocity.”? How we differentiate between they are both moving or only one of them is moving?

Diego- You are right. The conclusions do come fast. The challenge is that the conclusions come out of math that is beyond the scope of the course. We encourage you to dig deeper and share what you find with others here. You may find there is a group of Scholars interested in pursuing the same thing.

Thanks for commenting, Destiny! There is a real philosophical side to these aspects of physics. I look forward to hearing your thoughts/ideas as you go along!