Zeus lusted after Metis. He hunted her like prey.
Metis desperately tried to escape, changing her form many times, but Zeus eventually had his brutal way. Wasn't the first time, either.
Afterwards, he began to worry if Metis might be pregnant. So he ate her. He tricked her into taking on the likeness of a fly, then swallowed her like a Morning After Pill.
Of course, Metis was up the duff and was pretty pissed at her situation.
She knew her child would be vulnerable with a father like Zeus, so she decided to protect her with her own suit of armour.
She started hammering out a helmet and Zeus developed a headache the size of a hangover. In agony, his screams could be heard all over the world.
The gods assembled.
The fleet-footed god of commerce realised what was going on and directed the crippled god of craftsmen to cleave Zeus's skull with an axe.
In spite of his efforts, from out of that serial rapist's head, the god of wisdom was born. A fully formed woman, dressed for battle.