Some people test themselves with great tasks, pushing to the limits of endurance and suffering, hoping to forge it within. Only they will know how successful they've been, and how "real" they are inside.
When life is easy it can seem dreamlike, as when you're on vacation in the Caribbean, maybe floating on a raft in sunlit water, drink in hand, with every hunger satisfied. It's wonderful to relax and savor the dream, for a while, until boredom sets in. We crave adventure and discovery as much as any vacation, and want to feel "really" alive. But the "real" world brings great discomfort, too, and is often filled with difficulties and challenges. This is where we can excel as much as anyone.
Pain causes us to believe in "reality", when the mind is overtaken by the awful, unwelcome truth of agony. When it won't go away, it's deeply frightening. This is true suffering.
Pleasure erases pain, compensates us for it, and also reinforces the feeling of "reality". Eventually the memory of pain may vanish. Which is stronger over the long run, pleasure or pain? The jury seems to be out on that.
If we know someone who is suffering, particularly a close friend or relative, our empathy can cause indescribable pain and suffering. Even if it's a delusion caused by a serious mental illness like paranoia, we will suffer. So it is our thoughts and feelings that afflict us most, and this is what religion is supposed to help us with.
"Suffering is the rock upon which all religions founder", a sage once said. The ship of religion may founder on the rocks but still recover, which is a job for the faithful. It's a huge problem with no earthly solution. But we will understand the reason for suffering when we pass beyond this earthly realm.
Our knowledge of reality, then, is bordered by major limitations, such as pain, pleasure, and death. How "real" can anything be that is destined to turn to dust? We and everything we know will disappear in time and be forgotten to this world. Which is why we need to know God, who will never forget or abandon us .
God is the one, supreme, eternal, and fixed Creator of Reality; beyond time, space, and the notion of death. Every major religion agrees on this point, because everything known and unknown - seen and unseen - was created by the Super Intelligence of mind and heart which we call God.
What we call "reality" can never be the whole reality, because so much is hidden from us. The invisible worlds of atomic particles, viruses, and bacteria here on earth are a universe of their own. Size matters, but we are infinitesimal compared to the vast cosmos we see in the night sky; which is a tiny sliver of the cosmos. The difference between what we see in the night sky with our eyes, and what we see with telescopes, is like the difference between 0 and infinity.
Here's an example of the unreality of existence. All matter in the universe - as we know it - is mostly space, and empty:
How then can our lives have any importance? This is why: "All the world's a stage, and all the men and women merely players; they have their exits and their entrances, and one man in his time plays many parts." As You Like It; Act II, Scene IV - William Shakespeare.
"Do you not know that the body is the temple of the Holy Spirit within you, which you have of God, and that you are not your own?" The Apostle Paul, I Corinthians, 6:19-20
Human existence is a drama designed to expose the great truths of good and evil, and their consequences. It is a school, a training ground, and a temporary abode; not a resort. If all we seek is pleasure, we will never find it.