Is it possible that Jesus never laughed or smiled during His public life ? Are there verses in the Gospels which directly or indirectly bring out the sense of humor which Jesus ought to have had ?
Luke 13:19: It is like a grain of mustard seed, which a man took, and cast into his garden; and it grew, and waxed a great tree; and the fowls of the air lodged in the branches of it.
Middle eastern mustard (s. hirta) does not grow into great trees, but is for farmers a noxious weed. Rex Wyler, in The Jesus Sayings, page 111, believes the parable of the mustard seed is a parody of a common Jewish reference from the books of Ezekiel and Daniel, about a tiny sprig growing to become a giant "noble cedar” with roots that spread across the earth, branches reaching to heaven, fruit for all, and shelter for animals and birds. Wyler says the parable of the leaven in the flour, in the following verses (Luke 13:20-21; Matthew 13:33), appears to satirise a story (Genesis 18:6) about Sarah, who used three measures of choice flour to bake cakes for heavenly messengers visiting Abraham. The coincidence of two successive parables that seem to parody Jewish beliefs makes it quite likely that either Jesus or the source who reported his sayings had a subtle sense of humour.
In John's Gospel, Jesus sometimes tricked those who opposed him, by using double meanings that left his opponents confused. A well-known example is when John has Jesus tell Nicodemus that he must be born 'anothen', a Greek word with two meanings, enabling John to make Nicodemus look foolish. In Jesus' meeting with the Pharisee Nicodemus, he told him, "Verily, verily, I say unto thee, except a man be born anothen, he can not see the kingdom of heaven". Nicodemus understood this Greek word to mean 'again'. This is one meaning it can have, but it can also mean 'from above', a fact that John's Greek-speaking readers would have understood. In this case, Jesus was enjoying himself at the expense of Nicodemus. This does not work in English, so translators have to choose whether to use 'again' or 'from above':
John 3:3 (KJV): Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.
John 3:3 (NAB): Jesus answered and said to him, "Amen, amen, I say to you, no one can see the kingdom of God without being born from above.
A classic example of Hellenic Punnery is Matthew 16:18, where Jesus makes a pun out of Peter's name to deliver a theological lesson:
Matthew 16:18 (NKJV)
18 And I also say to you that you are Peter, and on this rock I will build My church, and the gates of Hades shall not prevail against it.
Peter had just delivered the statement of faith upon which the Church of Christ would be built. Peter in Greek is "petros", and means "a rock that can be moved", and the word in the Greek for "rock" in the phrase "on this rock" is "petra" which is a rock that cannot be moved. There is yet a third term which is "lithos" (where we get "lithography" from) which is more of a generic term, and can mean either. So Jesus basically said to Peter (who would later deny Him 3 times):
"you are the little, movable rock, but upon the immovable rock of the declaration that I am the Messiah, the Son of God, I will build my Church."
There is also of course the "camel through the eye of a needle" instead of simply saying "it is impossible" (which He went on to say after anyway). As well as pointing out the "righteousness" of the Pharisees. All of which have definite comedic effect. The question of course, is if anyone laughed when He delivered these. (The NT tells us that people often didn't understand what Jesus was talking about, even His own disciples, and sometimes were even too scared to ask.) Case in point? People have taken the camel statement literally, and have created an entire interpretation to say there was a gate in Jerusalem called "Eye of the needle" that had really low clearance, and a camel could go through it, but it had to do so on its knees.. a reference to humility. Which is not at all what the context of the passage teaches. Nevermind that there has never been such a gate.
Jesus saw Nathanael coming towards him, and said of him, Here comes one who belongs to the true Israel; there is no falsehood in him. 48 How dost thou know me? Nathanael asked; and Jesus answered him, I saw thee when thou wast under the fig-tree, before Philip called thee. 49 Then Nathanael answered him, Thou, Master, art the Son of God, thou art the King of Israel. 50 Jesus answered, What, believe because I told thee that I saw thee under the fig-tree? Thou shalt see greater things than that.
I find this to be quite humorous (although another person meantioned it first).
Some other user mentioned G. K. Chesterton's Orthodoxy (which is basically required reading for contemporary Christians, IMHO). Chesterton was a humanist, and constantly reminds us that Christ is as much Man as He is God, as the Creed teaches.
Following this spirit, I personally meditate on some of the basic human things that Christ did, like scratch his toes, sneeze, sleep, eat, laugh, cry, and even have bad breath (what if Christ snored?). Remember, none of these things are sinful, just what the average man experiences every day (which anyone who knows anything about Chesterton would understand what he would think of this right away). I don't mean this in any disrespectful way either: I mean this in a very innocent way. The idea that God woke up mornings to clean the "sand" out of His eyes fills me with awe.
So to answer your question, yes, Christ was human, had friends, and friends like to tell jokes sometimes. But to explain what I'm saying better than myself, let's end with Chesterton's Orthodoxy:
And as I close this chaotic volume I open again the strange small book from which all Christianity came; and I am again haunted by a kind of confirmation. The tremendous figure which fills the Gospels towers in this respect, as in every other, above all the thinkers who ever thought themselves tall. His pathos was natural, almost casual. The Stoics, ancient and modern, were proud of concealing their tears. He never concealed His tears; He showed them plainly on His open face at any daily sight, such as the far sight of His native city. Yet He concealed something. Solemn supermen and imperial diplomatists are proud of restraining their anger. He never restrained His anger. He flung furniture down the front steps of the Temple, and asked men how they expected to escape the damnation of Hell. Yet He restrained something. I say it with reverence; there was in that shattering personality a thread that must be called shyness. There was something that He hid from all men when He went up a mountain to pray. There was something that He covered constantly by abrupt silence or impetuous isolation. There was some one thing that was too great for God to show us when He walked upon our earth; and I have sometimes fancied that it was His mirth.