Which of course is your own personal interpretation of 2 Pet 1:20.
From Albert Barnes' Commenatary:
Is of any private interpretation - The expression here used (ἰδίας ἐπιλύσεως idias epiluseōs) has given rise to as great a diversity of interpretation, and to as much discussion, as perhaps any phrase in the New Testament; and to the present time there is no general agreement among expositors as to its meaning....
No it is not; I merely explained the teaching of the Apostolic Church.
A. 1Jo 2:27 But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him
B. 2 Pe 1: 19 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: 20 Knowing this first, that no prophecy of the scripture is of any private interpretation.(exposition) 21 For the prophecy came not in old time F4 by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
It is obvious that the above are saying 2 different things if we see "A" as saying that the Holy Spirit inspires individuals to understand the things of God, to include the correct interpretation of scripture, and if we see "B" as saying that individuals cannot come to understandings of scripture on their own.
However, let God be true and every man a liar. Better to look for another answer than to say that God is confused.
2 Pe 1:21 gives the context for 2 Pe 20, and says very simply that prophecy did not come of "the will of man." This is intended to be synonymous with the foregoing statement in v. 20 that no prophecy in scripture CAME ABOUT by virtue of some individual's personal exposition or explanation.
In short, this verse is dealing with the ORIGIN of scripture, and not with our present day interpretation of scripture.