Johnny’s mother had three children. the first child was named april. the second child was named may. what was the third child’s name?

Trying to fill up a seive with sand

Explanation:

This excerpt is from the book Fahrenheit 451  authored by Ray Bradbury in 1953,

'Montag tries desperately to memorize part of the book -- particularly the line "Consider the lilies of the field; they toil not, neither do they spin" -- the noise is so distracting that he forgets the words as soon as he reads them. Montag is reminded of a childhood memory, of trying to fill up a sieve with sand: right now, he feels as if his mind is a sieve and the words are falling out of it.'

The Sand represents the knowledge that he seeks and The sieve represents Montag's desire to pour books and knowledge into his brain, but how "he read and the words fell through.