Do you mean to tell me’, he growled a the Dursleys, ‘that this boy- this boy! - knows nothin’ abou’ - about ANYTHING?’Harry thought this was going a bit far. He had been to school, after all, and his marks were’nt bad.’I know some things,’ he said. ’ I can, you know, do maths and stuff.’But Hagrid simply waved his hand and said, ‘About our world, I mean. Your world. My world. Yer’ parents world.’ ‘What world?’Hagrid looked at though he was about to explode.‘DURSLEY!’ he boomed.Uncle Vernon, who had gone very pale, whispered something that sounded like ’Mimblewimble’. Hagrid stared wildly at Harry.‘But yeh must know about yer mum and dad’, he said. ’I mean, they’re famous. You’re famous. ‘What? My - my mum and dad weren’t famous, were they?’‘Yeh don’ know... yeh don’ know...’ Hagrid ran his fingers through his hair, fixing Harry with a bewildered stare.‘Yeh don’ know what yeh are?’ he said finally.Uncle Vernon suddenly found his voice.‘Stop!’ he commanded, ’stop right there, sir! I forbid you to tell the boy anything!’A braver man than Vernon dudley would have quailed under the furious look Hagrid now gave him; when Hagrid spoke, his every syllable trembled with rage.‘You never told him? Never told him what was in the latter Dumbledore left fer him? I was there! I saw Dumbledore leave it, Dursley! An’ you kept it from him all these years?’‘Kept what from me?’ said Harry eagerly.‘STOP! I FORBID YOU!’ yelled Uncle Vernon in panic.Aunt Petunia gave a gasp of horror.’Ah, go boil yer heads, both of yeh,’ said Hagrid. ‘Harry - yer a wizard.
J.K. Rowling, Harry Potter and the Sorcerer's Stone
finding-out-you-re-a-wizard, hagrid, harry-potter