I'm not a traditional theist, but your question implies that you mean "non-religious", so:
For the theists, do you grasp the idea that us atheists are just fine without relgion? No afterlife. No creator. No god watching over us?
Or do you think you have something special no non believer can experience? Happiness ,joy, love, fulfillment, wonder.
Define "fine". Most people seem pretty miserable much of the time, regardless of their philosophical positions.
That said, I don't think "joy and wonder" require accepting a label, nor that atheists are ignorant of faith, community, mystic insight, or euphoria, superficially offended though many might be by the suggestion that there is anything religion-ish about their lives. It's very clear to me, dealing with young Zoomers all day long, that they have found a lot of ways to replace the emotional support and communal truth-making that religion used to provide, from fictional fandoms to political cults. I'm not concerned that religion, if defined by function rather than aesthetics, is in any danger of extinction, certainly not from atheism. The younger generation never believed in gods to begin with, but they aren't ignorant of them, they just find them in other places and call them by other names. The line between Jesus and Harry Potter is a thin one if you're looking at how they effect lives rather than ontological assertions, and even the latter line is blurry (observe how that fandom is suddenly at war with the author who ostensibly created it over who her characters "really" are and what they "really" stand for.)
Now, are you cut off from some experiences you might otherwise have? Of course. Spiritual forces are at work in your life, and you aren't able to see them clearly; a lot of things happen to you that you must not quite understand, or must put yourself through mental contortions to reframe in terms of science or logic or other aesthetically acceptable magisteria. And you're definitely cut off from other people and communities, and any experiences that you might have if you were building bridges instead of walls between yourself and others. Atheism is inherently philosophically conservative, and you suffer from many of the downsides of conservatism as well as the advantages. Social isolation and inability to practice syncretism are downsides, but on the other hand absence of distraction and dedication to certain core principles can also be great advantages. You're apt to do better at certain things, or pursuing certain fields, where a religious affiliation would only be a barrier to success.