He has tried to reason with me on his past birthday that he was not 3, but 5 and going to school too.
Another thought... Some schools post preschool or kindergarten readiness checklists for parents. While helping him learn in his areas of interest, you may wish to use a checklist found online (or make one of your design) to show him what a school would look for in an incoming student. Many kids enjoy the experience of working with checklists, and the sense of accomplishment from a goal completed.
Seeing how far he is beyond what a preschool or kindergarten would expect from a student upon entrance may help him realize that school may not be the panacea he envisions. This may help him keep exploring topics to learn more about, and reinforce the habit of keeping a record of what he is learning about. This may be helpful for future advocacy.
