As you mentioned and as is stated in the Bible in Matthew 24:36, "Concerning that day and hour nobody knows, neither the angels of the heavens nor the Son, but only the Father." Jehovah God, Jesus, and the Holy Spirit are three separate entities. They do not form a trinity. In fact, the word trinity is not even mentioned in the Bible. When Jesus was here on Earth, he stated various times that his father, Jehovah, was greater than him and was God. "You heard that I said to you, I am going away and I am coming back to you. If you loved me, you would rejoice that I am going my way to the Father, because the Father is greater than I am" (John 14:28).
In the Christian religion God is the Father of Jesus. Once descended Jesus became the Holy Spirit. All Forms of God. However each does not know the mind or thought if God. And God has been known throughout time to change His mind.
One AND three. Three separate beings yet One. Its a God concept. One of those places faith comes in because our human minds cant fully understand it. God can keep anything He wants from anyone He wishes. He doesnt want anyone else to know until He is ready then they wont know.
Jesus was a man. A man cannot be a god. Jesus never said anything that would suggest he believed in the triune god idea. Jesus was misguided in many of the things he said, but nothing he ever said suggests trinitarianism. That idea evolved much after Jesus died, and I guess was easy to understand for the masses of pagans who converted to Christianity. But logically it cannot be derived from the NT, and it's internal logic is absurd. Three cannot be one, Jesus cannot be 100% man and 100% god at the same time, as those are mutually exclusive things. Christianity is based on a logical flaw. In reality, there is One God, Adonai, and Adonai alone (cf. Deuteronomy 6:4).
The truth about the Son of God is timely and soft. God the Father gave the title of God to his son when he gave his body a physical/spiritual births, but that is for a time and a purpose. But when the time and the purpose shall pass, Jesus will surrender the title and the throne "of God" back to God the Father, who gave it to him. "When he has done this, then the Son himself will be made subject to him who put everything under him, so that God may be all in all." 1cor15:28 So yes. There are things that Jesus didn't know (and was surprised by) here on earth and still doesn't know in heaven. That is so because it is not important to God/Jesus/and us! What is important is the fact that Jesus knows his father better than any of us or any of the angels, and that makes him a most worthy candidate. For example: David was stupid in comparison to Solomon, yet David knew God better than Solomon, therefore a better king. When dealing with God it's the heart that matters more than the mind. And that is because God doesn't need our mental help, but He can sure use a person of great character. (At least this is what I understood from the bible). I hope this helps?