Peter’s original name was Simon. Christ Himself gave him the name Cephas or Peter when they first met and later confirmed it. This name change was meant to show both Peter’s rank as leader of the apostles and the outstanding trait of his character — Peter (in Hebrew Kephas) the Rock.
His "always" name was Simon.
John 21:
15 When they had finished breakfast, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Feed my lambs."
16 A second time he said to him, "Simon, son of John, do you love me?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Tend my sheep."
17 He said to him the third time, "Simon, son of John, do you love me?" Peter was grieved because he said to him the third time, "Do you love me?" And he said to him, "Lord, you know everything; you know that I love you." Jesus said to him, "Feed my sheep.
What happened to his "Rockiness"?
“This name change was meant to show both Peter’s rank as leader of the apostles......”
Wrong.
1 Peter 5:1-3 - “So I exhort the elders among you, as a fellow elder and a witness of the sufferings of Christ, as well as a partaker in the glory that is going to be revealed: shepherd the flock of God that is among you, exercising oversight, not under compulsion, but willingly, as God would have you; not for shameful gain, but eagerly; not domineering over those in your charge, but being examples to the flock.”
Peter refers to himself as simply a “fellow elder”. Not senior elder, not head elder, or any other bogus title.