As Jaques explains to Duke Senior in Act 2 Scene 7 of As You Like It (now out of copyright):

All the world’s a stage,

And all the men and women merely players;

They have their exits and their entrances,

And one man in his time plays many parts,

His acts being seven stages. At first, the infant,

Mewling and puking in the nurse’s arms.

Then the whining schoolboy, with his satchel

And shining morning face, creeping like a snail

Unwillingly to school. And then the lover,

Sighing like a furnace, with a woeful ballad

Made to his mistress’ eyebrow. Then a soldier,

Full of strange oaths and bearded like the pard,

Jealous in honour, sudden and quick in quarrel,

Seeking the bubble reputation

Even in the cannon’s mouth. And then the justice,

In fair round belly with good capon lined,

With eyes severe and beard of formal cut,

Full of wise saws and modern instances;

And so he plays his part. The sixth age shifts

Into the lean and slippered pantaloon,

With spectacles on nose and pouch on side;

His youthful hose, well saved, a world too wide

For his shrunk shank, and his big manly voice,

Turning again toward childish treble, pipes

And whistles in his sound. Last scene of all,

That ends this strange eventful history,

Is second childishness and mere oblivion,

Sans teeth, sans eyes, sans taste, sans everything.

(Note the somewhat prejudiced attitude of the schoolboy to schooling, even in 1599.)

I still have my teeth.