If I told you that a flower bloomed in a dark room, would you trust it?
The “flower” is Kendrick (pause) and the dark room is his hometown, Compton. Plants (flowering or otherwise) require exposure to light to grow, as they use the energy from that light to transform carbon dioxide into sugars (that the plant feeds on) and oxygen (which the plant has no use for and expels back into the atmosphere). This process is called photosynthesis and is illustrated in the graph below.
Kendrick asks the girl if she trusts him and believes that he turned out to be a good and decent man despite the fact that he grew up in a hood riddled with violence and gang warfare, knowing it seems difficult to believe this is possible.
The reiteration of this line from the first verse suggests an emphasis on the figurative idea of trust in relation to the flower.
This could also be metaphoric to love between two people blooming in an unorthodox way; a one night stand or in a club, both physically and metaphorically darker places.
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