I think you're talking about "As You Like It" by Shakespeare.  In the play, there is a very famous speech ("Seven Ages of Man") by the character of Jaques that sounds somewhat like the lyrics you're describing.

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 ages...
(II, vii)

The monologue then goes on to describe those seven stages: Infant, Schoolboy, Lover, Soldier, Justice, Pantaloon, Second Childishnes.  Shakespeare provides terrific images for each of these stages.