Difficult to believe and difficult to understand

"The attainment of Buddhahood by plants and trees signifies the achievement of Buddhahood by insentient beings...Thef act that Toba  (memorial tablets) are constructed and the eye-opening ceremony for them is performed when we common mortals pass away indicates  that plants and trees attain Buddhahood as we attain Buddhahood in death." (HSG, page 522) -- "Somoku Jobutsu Sho"("On the Attainment of Buddhahood by Plants  and Trees")