We have to accept that the universe as we experience is largely if not entirely illusion. It is not, however, delusion.

By that I mean that our experiences are not what we experience, but they are something. The illusion of hardness, for example, is not real, since there are vast spaces between and within the atoms that make up something we think is solid. But there is a reality -- electromagnetic forces -- underlying the illusion.

That counter-intuitive things exist is a given. My intuition is that people on the other side of the earth should fall off. 

My intuition makes the constancy of light speed in a vacuum regardless of the motion of the observer very difficult to get my arms around, and I have worked on it for a long time, each time thinking I have it seeming to lose it again.

This brings me to ask my view of quantum mechanics, mainly the aspects of it that are commonly called quantum weirdness, such as the interpretation of it that the observer influences the outcome or that there can be the famous "spooky action at a distance." No, I have no "understanding" of all that and agree completely that it is counterintuitive. It is nevertheless both real and true, with the understanding that this is an empirical, not logical, conclusion, but we must be ruled by the outcome of experiment when repeated over and over with extremely precise agreement in the results. All that is above my pay scale and I can only see the detail from a very high altitude (don't complain about my mixing metaphors -- I like them).

The one thing I would not do is try to draw spiritual or similar conclusions -- such as that mind exists independently of matter (which I think is probably so but not for quantum reasons) or the brain gets free will from quantum uncertainty. One should take the theory only so far as it goes.