The meaning and origin of the expression: Make an ass of yourself

What's the meaning of the phrase 'Make an ass of yourself'?

To make an ass of your self is to behave absurdly.

What's the origin of the phrase 'Make an ass of yourself'?

This expression is first found in Shakespeare's A Midsummer Nights Dream, 1600, in which the weaver Nick Bottom has his head magically transformed into that if a donkey by the fairy Puck:

This is to make an asse of mee, to fright me, if they could.

An example in print that includes the currently common 'yourself' appears as late as the 19th century, in the novel by Anthony Trollope, The Belton Estate, 1866:

'I shall never marry.'

'Nonsense, Will. Don't make such an ass of yourself as to suppose that you'll not get over such a thing as this.