Where do you get that idea? Please in the future, please provide a source when you make a claim. It will save time and aggravation for all.
I am surprised that in a period where so much was written and so much survived no one thought to mention such amazing things.
Why do you thing there are no contemporary sources for Jesus?
We have lost a lot from that period. We don't have any of the original biographies of Alexander the Great written by his contemporaries, only later biographies written centuries later survived. It would not be strange if contemporary accounts of Jesus were lost. In his time and a couple centuries later Jesus was important only to his followers. To most pagan writers he was a nobody. The crowds he attracted were in some rural province of Galilee, attracting crowds of ordinary farmers and sheppards, and old women and young children, exactly the kind of people that these contemporary writers would not have the least interest in. He did not lead any army to attract the notice of the contemporary writers, and large peaceful crowds of peasants would not have interested them.
Jesus did most of his miracles among the people of Galilee and the contemporary writers likely felt little interest in someone healing a bunch of nobodies, and any reportd they heard would be second or third hand hand and dismissed as rumor.
Only his fillowers would have had any interest in Jesus. The letters of Paul date from a mere decade or 2 after Jesus and Paul dealing with people who knew Jesus, and since most of Jesus' would have illiterate fisherman and such, the lack of earlier writing is to be expected. The 4 Gospels were written from 40 years after Jesus death. well within the lifespan of eyewitnesses, to 70 years later, at the end of the lifespan of any eyewitness. Any gospel written after this time period were rejected. From an early time the 4 gospels were the only ones regarded as authentic.
All this contrast to Islam, whose first biography of Muhammad dates to a hundred years or more after his death, when all potential eyewitnesses to his life would have been dead. Nor is there any excuse for this gap in Islam, since Muhammad and his followers had scribes who could have written Muhammad's life. Plus as ruler of Arabia, should have attracted attention of other rulers, but we don't have any account of Muhammad from contemporary rulers.