As a child of both Shiva and Vayu, Hanuman was naturally very different from other monkey children.  Like most children, he was highly curious and wanted to explore everything around him. One day he saw the sun in the sky and not knowing what it was, he thought it was a ripe fruit and wanted to eat it.  He flew towards the sun at once to pluck it and devour it.  On the way, he saw Rahu the dragon.  For the young monkey-child he thought Rahu was a flying worm and wanted to eat that too. Rahu tried to escape from this crazy monkey-child who continued to follow him all over the place. Tired, Rahu prayed to Indra who was angry that a monkey was causing all this trouble.  He set off to chase Hanuman with his thunderbolt riding on his elephant Airavata.

But nothing scared the young Hanuman.  Now seeing Airavata, he was distracted by the new toy and flew towards it!  This greatly surprised Indra.  In anger and to stop this cheeky monkey, he struck him with his thunderbolt.  Hanuman fell to the earth severely injured on the chin.  When Vayu saw his son struck down, he flew to save his son. When he realized what Indra had done, he was very angry.
He drew in a mighty breath and sucked all the air from the Universe saying, “Let all those who harmed my son choke to death!”

This alarmed the gods as without air nothing would survive.  All the gods, including Indra ran to Vayu and tried to console him and calm him down. They apologized to him many times for the mistake of Indra and began to shower many blessings and powers on Hanuman.

Brahma, the Creator granted immortal life.

Vishnu, the Protector blessed him to be the greatest devotee of the God.

Indra whose thunderbolt had injured him, stated that no weapon of any kind will ever wound him again. Agni said, “No fire will ever affect you in any form.” Kala protected him from any kind of death. All the Devas and Gods together blessed him with the greatest strength and speed.

Hearing all these grand blessings from the Devas, Vayu was very happy and returned all the air back to the Universe. He led Hanuman safely back to Earth.

Hanuman’s pranks continued.  Being full of mischief, he made full use of his powers to disturb meditating sages by taking away their belongings or disrupting the items they used for their worship plus doing many other pranks. The sages were quite tired of all this and decided to put a mild curse on him since he was still only a child. Their curse was that he would recall his powers and capabilities only when someone reminded him about it. Thus later in his life as an adult, when the vanara army were deciding who would jump across the ocean to Lanka to find Sita, Hanuman sat quietly in a corner, looking helpless. It was then that an old and wise ape by the name of Jambavan reminded him of his powers. And when Hanuman realized the extent of his divine powers, he took a flying leap to Lanka and let nothing stop his journey to find Sita.