Answer
The experience of the spiritual world is completely different from that of the material world. The only way we can understand it while still situated in the material world is through careful reflection and guidance from scripture.
What we experience as pleasure in the material world is not real, but illusory. Yet the very presence of this illusory pleasure indicates that real pleasure must exist elsewhere.
For example, a person in a desert may see what appears to be a water body at a distance. This creates the impression of water, but when one approaches it, there is no water there. It is a mirage. The absence of water in the desert does not mean that water does not exist at all; rather, it indicates that real water exists somewhere else.
Similarly, in the material world there appears to be pleasure, but upon close examination it is temporary and incomplete. This suggests that real, complete, and lasting pleasure must exist in another realm.
That real pleasure is found in the spiritual world, the realm of spiritual reality.
We can begin to understand this by hearing from scriptures, studying authentic Vedic literature, and engaging in devotional service. Through this process, the nature of the spiritual world, spiritual existence, and true spiritual happiness gradually becomes clear.