It's only "intellectual theft" because we consider peoples thoughts their own property. On many levels, that doesn't really make sense to me.

Tons of historical documents have shown that inventions, mathematical proofs, and celestial observations were made by humans separated by continents and time. What that shows is that it is certainly possible for two persons to have the same exact or similar thought without ever having been influenced by the other.

Think about it. Copyright and trademark are only a thing because of the constraint of the speed of light (or as some people believe, the constraint of the simulation running the universe). In an infinite universe, everything that has ever been invented or created by a human has already happened thousands of times in another place and another time.

I want to add, to give credit where credit is due, that this thought was conveyed to me in first grade by another 1st grader sitting with me at the lunch table. That was a day and conversation that I will never forget. 1972.