How does the boy's mistake about "filthy lucker" from "The Rocking-Horse Winner" by D.H. Lawrence clarify his mother's thinking and her motivations?
The young Paul mistakenly—yet unsurprisingly—mixes up two words that sound alike: lucre and luck (or "lucker"). Lucre, which means money, is pronounced with a long u in the middle and an "er" sound at the end. Lucker is pronounced with a short u in the middle but otherwise the same way as lucre. Therefore, Paul thinks lucre means luck.
When his mother defines luck as what gets you money—not love, happiness, security, a home, and so on—she reveals her singleminded obsession with money. She then goes on to say that luck is better than money, because money can run out, but with luck you will always "get more money." This shows her addiction to money. Like a drug addict, she always needs "more." One "fix" leads to the desire for another, bigger fix. And like an addict, she will destroy other people to get her fix, because the drug, in this case money, is the most important thing in the world to her. Unfortunately, Paul, a child desperate for his mother's love, doesn't fully understand what he is dealing with.