Let’s say you want to become an expert on the sun. What would that mean? That you know its temperature, its cycles, its various wavelengths. But you still only know the sun from a great distance.
So you build a ship and go to the sun. To survive the trip, you’d need to filter the sun’s light down to human levels, and redirect away most of the heat, and you’d have very few instruments that could function under so much radiation and magnetism.
In the end, the best you can do is become an expert at observing the sun, and then only from the confines of a human level of perception. As close as it may be, the truth of the sun, its own sphere of being, is inaccessible to creatures like us.
Multiply this by infinity and you’ll have some notion of the problem.