Nathanael did see greater things. He was one of those to whom Jesus appeared on the shore of the Sea of Tiberias after his resurrection (see John 21:1-14). They had been fishing all night without success. In the morning, they saw someone standing on the shore though no one knew it was Jesus. He told them to cast their net again, and they made so great a catch that they could not haul the net in. Then John cried out to Peter, It is the Lord.
When they brought the boat to shore, they found a fire burning, with some fish laid on it and some bread. Jesus asked them to bring some of the fish they had caught, and invited them to come and eat their meal. John relates that although they knew it was Jesus, none of the apostles presumed to inquire who he was. This, John notes, was the third time Jesus appeared to the apostles.