Why does Cassius say i have exposed my naked chest to the thunder bolt?

Cassius uses the phrase "I have exposed my naked chest to the thunderbolt" to express his vulnerability and willingness to confront danger head-on. It symbolizes his readiness to face the consequences of his actions and the inherent risks of challenging those in power, particularly Julius Caesar. This metaphor highlights his bravery and defiance, as he acknowledges the potential for catastrophic outcomes while still choosing to stand firm in his beliefs.