Definitions for "Rags to Riches"
To be in the big blind with a hand you wouldn't call(ex. 2,3 os), but since you are in the big blind you check. With your rags(2,3 os), the flop comes A45. your rags just became riches.
Let's say you had a pocket pair of 3,4 off-suit and you almost want to fold. But because you are in the Big Blind, you just check and the Flop turns out to be A, 2, and 5. Wow! Your Rags (useless cards) became Riches.
The term "Rags to Riches" refers to any situation in which a person rises from poverty to wealth. This is a common archetype in literature and popular culture.