Human beings naturally rely on what they can see and on their own personal judgment when choosing how to live. Yet, paths that initially seem safe and comfortable often end in disaster. The primary approach among commentators is that such a path is not actually correct; it merely appears that way to the person walking it ([מצודת דוד]). This illusion of a proper path stems from a few different sources. Sometimes it is a matter of self-deception, where a person commits a wrong but convinces themselves that their actions are perfectly fine ([רש״י]). In other cases, the danger is simply hidden from view. The very first step might not be a clear wrong, but continuing down that specific route will inevitably result in ruin ([רלב״ג]). The greatest danger lies in relying on a subjective sense of morality. A person cannot be considered righteous simply because they act according to their own personal logic, as true righteousness is defined exclusively by God's commands ([עמנואל הרומי]).
To illustrate the sharp contrast between how a choice first appears and its final result, commentators point to a fork in the road between two opposing ways of living ([אלשיך], [מלבי״ם]). The path of the foolish and the material world is highly tempting and comfortable at its start. It offers immediate worldly pleasures, looks smooth and free of obstacles, and attracts those who lean toward laziness, much like the lifestyle chosen by Esau ([רש״י]). However, the end of this journey is suffering and destruction. Conversely, the path of wisdom initially looks harsh and covered in thorns, requiring a constant struggle against negative urges. Yet, it leads to a smooth existence and life in the World to Come.
The deceptive nature of a wrongful life is subtly reflected in a linguistic shift, moving from a masculine description at its start to a feminine one at its end ([אלשיך]). A bad path begins like a male, seemingly incapable of reproducing. Over time, however, it begins to "give birth," multiplying itself and spawning a wide variety of further wrongs and avenues of destruction.
Taking a completely different approach, [אבן עזרא] suggests that the straight path is not an illusion at all. Instead, it refers to the genuine path of God's Commandments placed directly in front of a person. The tragedy is not that someone was tricked by a bad path that looked good, but rather that they actively chose to abandon the truly straight path. It is as a result of this abandonment that they find themselves facing destruction.
Because human senses and logic are so easily fooled, a person must proceed through life with extreme caution. This requires a constant examination of one's habits and a continuous reliance on God's help to remain on the proper path ([ביאור שטיינזלץ]).