Unfortunately no one can. See Lucas v. Hamm, 364 P.2d 685 (Cal. 1961).
Apparently, according to the California Supreme Court, nobody can be expected to understand the Rule Against Perpetuities. That's why it has been made moot by statute in most jurisdictions.
Charles Nelson and Peter Wendel , A Possessory Estates and Future Interests Primer was helpful to me, in the very limited way in which I was ever able to grasp any of it.