In "Don Quijote of La Mancha," Miguel de Cervantes Saavedra emphasizes the importance of personal experience over preconceived notions. The character suggests that one should test their beliefs and ideas in reality before committing to them definitively. This highlights the value of skepticism and the necessity of deriving conclusions from firsthand encounters rather than solely relying on expectations.

The notion presented in the quote encourages readers to remain open-minded and willing to explore different perspectives. It suggests that even if something seems promising at first glance, true understanding comes from practical involvement. After gaining substantial experience, one should then compare the result to their initial expectations to form a more informed opinion.