When you have had a profound experience with the Spirit, it is hard to come back down from that “mountaintop” you have been on. Coming “down” or re-engaging the fallen world, only to find less spiritually inclined persons arguing, is distasteful.
There are many great things that are hard to understand unless you ask God. If you harden your heart you will not ask, and tragedy is inevitable for those with hard hearts (see commentary at 1 Nephi 17:41–42; Alma 12:31–37).
Because of the prophetic preview Nephi had just witnessed of the disastrous destiny of his descendants, he felt that his afflictions were “great above all.”