The Apostle’s were sharing Jesus’ words and telling of His works from the time that Jesus was alive until they died. They didn’t have to ‘try’ to remember back to anything when the Gospels and Letters were written. They shared the very same testimonies from the very beginning.
It most likely was not the Apostles who wrote the gospels. which were likely to have been penned from 55 - 95ad (John) by unknown authors writing under the pseudonyms of Mark, Luke, etc.....and these, including Paul's letters,
is the only account we have of the life of Jesus. And Paul seemed not to have known much about Jesus the man.
''No parables of the sheep and the goats, or the prodigal son, or the rich man and Lazarus, or the lost sheep, or the good Samaritan. In fact, no Jesus as teacher at all.
No driving out evil spirits, or healing the invalid at Bethesda, or cleansing the lepers, or raising Lazarus, or other healing miracles. As far as Paul tells us, Jesus performed no miracles at all.
No virgin birth, no Sermon on the Mount, no feeding the 5000, no public ministry, no cleansing the temple, no final words, and no Great Commission. Paul doesn’t even place Jesus within history—
there’s nothing to connect Jesus with historical figures like Caesar Augustus, King Herod, or Pontius Pilate.''
https://www.patheos.com/blogs/crossexamined/2012/12/what-did-paul-know-about-jesus-not-much/
