No, it would not be accurate to say that Einstein never nearly understood gravity or time. Albert Einstein is widely regarded as one of the greatest physicists in history, and his theories of relativity revolutionized our understanding of gravity, spacetime, and the nature of the universe.
Einstein's theory of general relativity, published in 1915, provided a new framework for understanding gravity. It introduced the concept of spacetime curvature, where mass and energy cause the curvature of the fabric of spacetime, and objects move along geodesics in this curved spacetime. General relativity successfully explained a wide range of gravitational phenomena, such as the precession of the perihelion of Mercury's orbit, the deflection of light by massive objects, and the existence of black holes.
Furthermore, Einstein's theories of relativity also had profound implications for our understanding of time. In special relativity, Einstein showed that time is not absolute but rather depends on the relative motion between observers. It introduced the concept of time dilation, where time appears to pass slower for objects moving relative to an observer at rest.
In general relativity, Einstein's theory extended these ideas by showing that gravity can also affect the flow of time. The presence of mass and energy causes time to flow differently in regions of different gravitational potential. This phenomenon is known as gravitational time dilation, and it has been confirmed by experimental observations, such as the famous Pound-Rebka experiment.
Einstein's contributions to the understanding of gravity and time are widely recognized and have been extensively verified by numerous experiments and observations. While there have been developments in our understanding of gravity and attempts to unify it with quantum mechanics, Einstein's work forms the foundation of modern gravitational physics and remains highly influential to this day.