Mark's Gospel, followed by both Luke and John, simply had Jesus ride into Jerusalem on a colt, but Matthew expanded the story, making it seem ridiculous:
21:2 Go into the village over against you and straightway you shall find an ass tied, and a colt with her, loose them and bring them unto me. 21:5 Behold thy king cometh unto thee, meek, and sitting upon an ass and a colt the foal of an ass 21:7 And they brought the ass, and the colt, and put on them their clothes, and they set him thereon.
So, in Mark, Luke and John, Jesus rode a colt or young ass into Jerusalem. In Matthew, Jesus rode both an ass and a colt, apparently at the same time.
The Passover.
jerusalem
Jesus died and rose from the grave
In the upper room of a house in Jerusalem.
John records Jesus' visits to Jerusalem, particularly at the times of the Passover feasts.
Simon of Cyrene happened to be in Jerusalem at the time of the crucifixion of Jesus. It is not explicitly stated why he was there, but it was likely due to his religious pilgrimage for the Jewish festival of Passover. It was a common practice for Jews to travel to Jerusalem during this time.
No Jesus rode the colt on Palm Sunday a week earlier.
First their entry was celebrated (Palm Sunday). They celebrated the Passover. Jesus was arrested, tried and crucified.
Jesus celebrated the passover meal with the apostles and some of his disciples in the upper room.
It is estimated that thousands of people attended the Passover in Jesus' day, as it was a significant religious event for the Jewish people. Jerusalem would have been crowded with pilgrims coming to celebrate the holiday.
I believe they travelled to Jerusalem to pay taxes and celebrate Passover while there. After leaving they finally noticed that Jesus was not with them. Frantic, they returned and found the 12 year old Jesus speaking in the temple.
He was in the temple reading and debating scripture with the rabbis and elders.