Will the Antichrist know he is the Antichrist?
The most expedient answer would be, "I don't know, and, neither does anyone else, for sure." With that frame of reference, we can offer some conjecture on the matter, based upon what God's Word tells us.
None of God's creatures is more intelligent than Lucifer, the fallen one, now called "that old serpent," "Satan," and "the devil." But Satan is not omniscient, as is God. That is, he doesn't know everything, and cannot precisely know what will happen in the future.
He can know in generalities what will happen, but not exactly when it will happen. God's children who study the Bible, and, particularly the prophetic portions of the Word can know roughly the same things as Satan with regard to what will happen in the future, so far as the Bible tells us. About God's omniscience (all-knowing), the Bible says:
"He hath made every [thing] beautiful in his time: also he hath set the world in their heart, so that no man can find out the work that God maketh from the beginning to the end" (Ecclesiastes 3:11).
Most likely, God alone knows who the "man of sin"--the Antichrist, will be at "the Beast's" entrance onto the world scene to sign the covenant of Daniel 9:26-27. It is interesting that some prophecy scholars have proposed that Satan has had a man prepared in every generation of mankind's history for the purpose of fulfilling the role of Antichrist. Some of these men might have included Antiochus Epiphanes, Nero, Napoleon, Hitler, and others.
Although Satan doesn't know precisely who the Antichrist will be, he knows that according to Scripture--God's truth--there will come forth the rider on the white horse of Revelation 6:2. Satan knows that this will be a man who sells out totally to Satan's plan to prevent Christ from ruling on Earth.
It stands to reason that if Satan doesn't know for sure who the Antichrist will be, until that man's appointed time, the man who will be earth's most terrible tyrant can't know that he is the Antichrist, until the time appointed.