Nephi has truly seen great things. As a part of his vision of the tree of life, he saw the entire history of the earth including the ministry of the Savior, the history of his people on the Americas, the Apostasy, the Reformation, the Explorers, the Pilgrims, the Revolutionary War, the Restoration of the Gospel, the coming forth of the Book of Mormon, the gathering of Israel in the last days, and finally, the end of the world as described by John the Revelator. See 1 Nephi 11-15. He saw things that were so great that the Lord commanded that they be withheld from the record.
“All who have been entrusted with a ‘high mountain’ or temple experience have been given knowledge that they are not at liberty to share. There are many sacred truths revealed to those worthy and ready to receive them that are ’not lawful for man to utter; neither is man capable to make them known, for they are only to be seen and understood by the power of the Holy Spirit, which God bestows on those who love him, and purify themselves before him’ (D&C 76:115-16).” (McConkie and Millet, Doctrinal Commentary on the Book of Mormon, vol. 1, p. 218)