Why is Athena birth so unusual?

Answer 1

it was unusual because she was born from zeus head after he ate his wife metis believing that the next child if a boy would be stronger than him and so he ate his wife to prevent that but zeus experienced a huge migraine and gave birth to athena his daughter through his head

Answer 2

The Greek goddess Athena's birth was unusual because she was born straight from the head of her father Zeus.

Some say she had no mother, but in other myths, Zeus laid with Metis, a Titan. He was afraid of the consequences and ate her whole, but it was too late: she was already impregnated.

One day, Zeus got a splitting headache. He asked Hephaestus to cut his head open with a double-sided axe (as he was immortal, it would not kill him). From Zeus' head sprang his daughter Athena, fully grown and in battle armour.