Isa 63:11 Then he remembered the days of old, Moses, and his people, saying, Where is he that brought them up out of the sea with the shepherd of his flock? where is he that put his holy Spirit within him?
The one who "remembered the days of old" is recalling the time when Moses brought the children of Israel out of Egypt. The one who "remembered the days of old" is asking where is God who did marvelous works.
You believe the believers prior to Day of Pentecost were "born again" in the same manner as believers after Day of Pentecost? Have you ever read Numbers 11? ... and specifically Numbers 11:25?
Numbers 11:25 And the LORD came down in a cloud, and spake unto him, and took of the spirit that was upon him [Moses], and gave it unto the seventy elders: and it came to pass, that, when the spirit rested upon them, they prophesied, and did not cease.
Read the whole record ... from vs 1 through vs 30.
You believe we are born again after Pentecost in the same manner as what occurred back then? You are incorrect in your understanding.
The Lord Jesus Christ told His disciples that He had to go away in order for the Comforter to come:
John 16:7 Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you.
and in John 14:26 we learn that the Comforter is the Holy Spirit:
John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
In Acts 1, just before Jesus ascended into heaven, He told His disciples:
Acts 1:4-5 And, being assembled together with them, commanded them that they should not depart from Jerusalem, but wait for the promise of the Father, which, saith he, ye have heard of me. For John truly baptized with water; but ye shall be baptized with the Holy Ghost not many days hence.
The giving of the Holy Spirit on Day of Pentecost was the "promise of the Father" spoken of by Jesus.
In Hebrews 11, after reading of many wonderful believers who lived prior to the birth of the Lord Jesus Christ, we are told:
Hebrews 11:39 And these all, having obtained a good report through faith, received not the promise
ForestGreenCook ... you've got some studying to do in order to understand what it is to be born again in our day and time.