Joseph Smith said:
"Now, I ask all who hear me, why the learned men who are preaching salvation, say that God created the heavens and the earth out of nothing? The reason is, that they are unlearned in the things of God, and have not the gift of the Holy Ghost; they account it blasphemy in any one to contradict their idea. If you tell them that God made the world out of something, they will call you a fool. But I am learned, and know more than all the world put together. The Holy Ghost does, anyhow, and He is within me, and comprehends more than all the world: and I will associate myself with Him."
Note that when Joseph Smith says he is learned, he is saying that he is learned in the things of God. He is contrasting himself with the learned men preaching salvation who are unlearned in the things of God.
In fact, he says "I am learned, and know more than all the world put together." He then says "The Holy Ghost does, anyhow, and He is within me, and comprehends more than all the world: and I will associate myself with Him."
This is a fascinating look into what the gift of the Holy Ghost meant to the prophet Joseph Smith. Since the Holy Ghost knows everything, Joseph Smith was willing to say that he knew more than all the world together, because he associated with the Holy Ghost.
In other words, his association with the Holy Ghost was such that the Holy Ghost was there as a constant instructor. Not a vague instructor, but one who could clearly convey knowledge that Joseph Smith accepted completely because he knew and recognized the source, and because he could hear the Holy Ghost with sufficient clarity that the Holy Ghost was his constant instructor, his mentor.
After baptism, I got the gift of the Holy Ghost, but I do not go around saying that I know more than all the world.
But that is a limitation I have placed on myself by my own behavior. Not that I am up to no good. But I must become a much better man, more obedient, more willing to submit my own will to the will of the Father as Jesus did, if I am to live up to my privileges as saints in the new testament did. It is all up to me.
We live far beneath our privileges. This shows us what the privilege of the gift of the Holy Ghost is meant to be, in part. It is no coincidence that one of the revelations state
D&C 76: 11 We, Joseph Smith, Jun., and Sidney Rigdon, being in the Spirit on the sixteenth day of February, in the year of our Lord one thousand eight hundred and thirty-two—
12 By the power of the Spirit our eyes were opened and our understandings were enlightened, so as to see and understand the things of God—
13 Even those things which were from the beginning before the world was, which were ordained of the Father, through his Only Begotten Son, who was in the bosom of the Father, even from the beginning;