Is there any knowledge about time travel being hidden from humans? Who is responsible for hiding it and why?

Time travel hasn’t been hidden from us at all. We simply fail to recognize that it has laws to follow just as everything else in physics.

If I ask you to think about the first place you remember living, your mind’s eye just took you to a place and time far away from the present moment. When we are not inhabiting a physical body, we don’t have the 3-D limitation of sequential time. If we are awake in human form, we are limited to “going there” via thoughts (astrally) rather than taking the body with us. It’s much like trying to take an ice cube into an oven set on “high.” Our astral selves are suited to time travel whereas our physical bodies are not.