I know there's no way for us to know until we get there, but I believe there are slivers of heaven - shadows of the reality of heaven - that we can see in our lifetime, but never fully grasp due to our limited faculties of perceiving and understanding reality. For instance, we see time as linear, whereas the concept of time will likely be entirely different in heaven, such that we would not feel the passage of time in a linear sense.

I think one sliver of heaven we can experience on earth is the intimacy between a husband and wife, for instance, being connected emotionally, spiritually, and physically in orgasm (I don't think anyone who has experienced this kind of multi-level intimacy would ever think about being bored or wonder how much time has gone by - you're just in bliss and in the moment). But I think this is just a shadow of the intimacy we will feel in heaven all the time, being at perfect oneness with God.