Perry,
Account involving Nicodemus is found in John chapter 3 which is a fabrication. For example, Jesus has supposedly said: "No one has ever gone into heaven except the one who came from heaven—the Son of Man.”—John 3:13
It means only Jesus who descended from heaven has gone into heaven, no one else has gone into heaven! Jesus ascended into heaven at the end of his ministry, after his death. Hence how could he say he has ascended into heaven at the start of his ministry?
When the writer of gospel of John wanted to put his words into the mouth of Jesus, see how unwisely he made it—he unwittingly gave a clue to the readers that it was fabricated.