If our sex life were determined by our first youthful experiments, most of the world would be doomed to celibacy. In no area of human experience are human beings more convinced that something better can be had only if they persevere.

The remark uses sexual learning as a vivid example of a broader human trait: early attempts are often awkward or disappointing, yet people persist because they believe improvement is possible. James contrasts the determinism implied by “first youthful experiments” with the reality that competence and satisfaction are usually acquired over time, through practice, patience, and resilience. The second sentence generalizes the point beyond sex, suggesting that perseverance is fueled less by certainty of success than by a stubborn, hopeful conviction that “something better” lies ahead. In that sense, the quote is both wryly comic and quietly optimistic about human adaptability.