Classics and Oscar Wilde

While I was reading the only novel of Oscar Wilde, The Picture of Dorian Gray, I got surprised by his many references to classical civilization. 
So, why this tendency to use metaphorical comparisons based on mythological characters or to refer the name of persons of ancient Greece and Rome?

"I really can't see any resemblance between you, with your rugged strong face and tour coal-black hair, and this young Adonis, who looks as if he was made out of ivory and rose-leaves. Why, my dear Basil, he is a Narcissus , and you _well, of course you have an intellectual expression, and all that."

"What the invention of oil-painting was to the Venetians, the face of Antinoüs was to late Greek sculpture, and the face of Dorian Gray will some day be to me."

"Yes,  he continued, I am less to you than your ivory Hermes or your silver Faun".

"He could be made a Titan or a toy. What a pity it was that such beauty was destined to fade".

"The praise of folly, as he went on, soared into a philosophy, and Philosophy herself became young, and catching the mad music of Pleasure, wearing, one might fancy, her wine-stained robe and wreath of ivy, danced like a Bachante over the hills of life, and mocked the slow Silenus for being sober."

"I had drawn you as Paris in dainty armour, and as Adonis withs huntsman's cloak and polished boar-spear".

"Where was the great crocus-coloured robe, on which the gods fought against the giants, that had been worked by brown girls for the pleasure of Athena? Where the huge velarium that Nero had stretched across the Colosseum at Rome, that Titan sail of purple on which was represented the starry shy and Apollo driving a chariot drawn by white gilt-reined steeds?



I read Wilde's biography and found the answer.

From 1871 to 1874 he read Classics with a scholarship at Trinity College, in Dublin, where hi was an outstanding student and won the University's highest academic award in Greek.

Then, during the next four years he studied Greats (ancient Rome, ancient Greece, Latin, ancient Greek and Philosophy)  at Magdalen College, in Oxford, graduating with excellent marks, as well.

Among his poems I discovered the following one:

Endymion, G.F. Watts, 1872.

ENDYMION

The apple trees are hung with gold,
and birds are loud in Arcady,
the sleep lie bleating in the fold,
the wild goat runs across the wold,
but yesterday his love he told,
I know he will come back to me.
O rising moon! O Lady moon!
Be you my lover's sentinel,
you cannot choose but know him well,
for he is shod with purple shoon,
you cannot choose but know my love,
for he a shepherd's crook doth bear,
and hi is soft as any dove,
and brown and curly is his hair.

The turtle now has ceased to call
upon her crimson-footed groom,
the grey wolf prowls about the stall,
the lily's singing seneschal
sleeps in the lily-bell, and all
the violet hills are lost in gloom.
O risen moon! O holy moon!
Stand on the top of Helice,
and if my own true love you see,
Ah! if you see the purple shoon,
the hazel crook, the lad's brown's hair,
the goat-skin wrapped about his arm,
tell him that I am waiting where
the rushlight glimmers in the Farm.

The falling dew is cold and chill,
and no bird sings in Arcady,
the little fauns have left the hill,
even the tired daffodil
has closed its gilded doors, and still
my lover comes not back to me.
False moon! False moon! O waning moon!
Where is my own true lover gone,
where are the lips vermilion,
the shepherd's crook, the purple shoon?
Why spread that silver pavilion,
why wear that veil of drifting mist?
Ah! thou hast young Endymion,
thou hast the lips that should be kissed.