“A man’s love is of man’s life, 'tis woman’s whole existence.” Is it saying a man is in love with his own affairs (with no room for a woman in it)??? The second half of the quote is self-explanatory.
FYI: The quote is from “Don Juan”, but I did not hear it in exprssed in its original context.
The full stanza makes the meaning unambiguous. It is from stanza 194 from canto 1 and is part of the letter that Donna Julia writes from the convent to which she has been sent after being caught having an affair with Don Juan.
*'Man’s love is of man’s life a thing apart,
'Tis woman’s whole existence; man may range
The court, camp, church, the vessel, and the mart;
Sword, gown, gain, glory, offer in exchange
Pride, fame, ambition, to fill up his heart,
And few there are whom these cannot estrange;
Men have all these resources, we but one,
To love again, and be again undone.
*
Woman wants monogamy;
Man delights in novelty.
Love is woman’s moon and sun;
Man has other forms of fun.
Woman lives but in her lord;
Count to ten, and man is bored.
With this the gist and sum of it,
What earthly good can come of it?