What is the meaning of the phrase, 'I cause laugh I've got gold mines in the poem

The line "cause I laugh like I've got gold mines digging in my backyard" from the poem Still I Rise is comparing the speaker's laughter to the abundance and wealth that comes from a gold mine. This simile conveys a sense of confidence, resilience, and power that the speaker possesses despite facing adversity.

The simile "cause I walk like I've got oil wells pumping in my living room" is similar. It also displays confidence, resilience, and power, but in a different way. The speaker's confident walk is likened to the constant flow of oil, which is associated with wealth and prosperity.