No, I was never one of those positive people who believes he can have whatever he sets his sights on. I just kept working at it.

Miller contrasts “positive thinking” or manifest-destiny confidence with a more workmanlike ethic of persistence. The speaker rejects the idea that success follows automatically from belief or visualization; instead, progress comes from sustained effort over time, often without certainty of the outcome. The quote implicitly reframes achievement as a product of process—showing up, iterating, and enduring setbacks—rather than a reward for optimism. It also carries a modest, anti-mythic tone: the author declines the heroic narrative of unwavering self-belief and offers a more credible account of how difficult creative or professional goals are typically reached.