I think it's in the beginning of Operating Manual For Spaceship Earth by R. Buckminster Fuller, where he says that he determined that he could predict advances

I think it's in the beginning of Operating Manual For Spaceship Earth by R. Buckminster Fuller, where he says that he determined that he could predict advances around 25 years out and still be reasonably accurate. After that, no bet. But people would still tell him he was a century ahead of his time. Anyway, same idea.