I remember some sage cursed Lord Hanuman for misusing his great powers and Hanuman forgot that he had special powers.
But how did he break the curse? How did he get to know that he has special powers?
Yes, Hanuman did forget his special powers due to the curse of the sages. But when the sages cursed Hanuman, they had also added the clause that whenever anyone would remind Hanuman of his glory, his powers will again arise:
yadā te smāryate kīrtistadā te vardhate balam [VR - 7.36.35]
- When you will be reminded of your glory, then your powers will increase.
So when during the search for maa Sita the time came to cross the ocean, Jambavan said among them Hanuman is only able to cross the ocean and reminded him how he was born of Vayu and how he has special powers:
स त्वम् केसरिणः पुत्रः क्षेत्रजो भीम विक्रमः ||
मारुतस्य औरसः पुत्रः तेजसा च अपि तत् समः | त्वम् हि वायु सुतो वत्स प्लवने च अपि तत् समः ||
वयम् अद्य गत प्राणा भवान् अस्मासु सांप्रतम् | दाक्ष्य विक्रम संपन्नः कपि राज इव अपरः || [VR - 4.66.29,30,31]
Such as you are, you are Kesari's son through his wife, oh, frightful pugilist, and you are the lineal son of Air-god, and even by your gusting you are selfsame to Air-god, and even by your flying also you are his selfsame to Air-god, in all respects.Presently we are as good as dead, and among us presently you are the only one rife with competence and valiance, you are the other Sugreeva, the king of monkeys, to us.
So after Jambavan reminded Hanuman of his powers and glory, as per the statement of the sages, the curse broke and His powers again increased.