Understanding that time is an illusion requires a fundamental change to the generally accepted understanding of reality. All events exist simultaneously. They only play out over time when viewed through a lens of separation that leads events to appear to be a linear, unfolding chain of causality.
Time both limits and separates us. It shapes our mortal experience. From the vantage point of non-physical consciousness (spirit), there is not an unalterable past or an unseeable future through which it can experience itself as being separate from the events that form its experience.
We have used the experience of time to shape our experience of the human self. However, you can alter your relationship with time such that you are its master, rather than its prisoner.
Opening to a different idea of time is one of the first experiences of coming to see through the illusion of space-time. What makes the contemplation of time more fascinating than physical matter is how it lends itself to be warped and played with