I don't have to imagine—and I should also say that not all people who experience suicidality have a "unipolar" dysphoria kind that was always present; some of us just happened to develop it later on, and or it just comes and goes; for some it only touches when one is super stressed and the usual methods of relaxing are not engaged or thinking methods to curb it end up going unapplied (perhaps due to being thrown off), or countless other circumstances / possibilities.
But to never know this darkness must be amazing. For that, yes that's a fantasy.
One can wonder if knowing darkness can only make the light feel brighter; and feel more precious, delicious, invaluable; and enjoyed. One forgets all dark when in all light—and the oure halo corona glow of but one good moment eclipses all other ones; and glazes (and blazes) over the shadow of all other moments of falling, and tripping; every misstep and harsh small impact, that led into one's feeling before that. An odd thing about our feelings: how they surpass each other, how they each take up whole spaces and do not leave room for their predecessor; so even if sadness may not take time to fully give space for joy (except for tactly twisted reminiscence; often knitpicked to weave whichever strand that the current other emotion wants to pull out of it), it seems that Joy does not take even but one moment to reinvoke sadness—or any other less pleasurable emotion, for that matter—it seems satisfied with itself: quite the humble emotion, if I may say so myself. A real low entropy state—not wishing for any thing else besides itself—unlike the other emotions (nigh all of them), which seem to almost be
characterized by a wish for changing, of rolling towards something; a will to move, an unease in the current place and state. It seems all the other states all point towards (and wish for) pleasure, joy, and serenity; and I believe it is their purpose to fall us into that serene state: a fine place: a good view to venture through, and a good stop to continue to revisit. The unfortunance of it being too included in the statement of fluctuation embodied in "this too shall pass" is much assauged by the fact that it may be returned to again. An allurance in that constant possibility. 'Au revoir' to joy, hope, and all forms of serenity—pure, impure; faint, intense; gentle, raw;—near, and far.
We are still travelling and visiting the locations, looking for fine things and places. We find them when we do—I think it a venture greatly worth it.
To the next horizon. (And sunset and sunrise and twilight and moonlight; night and day and the precarious space in between—and the many moments of sway in their deepest flows and currents; ode to all moments—and valediction for the ones to set out now and celebrance to their graduation; cheers to their recoming, and all the new becomings their feir rearrivals, revivals, and reprisals, will incite in them and us. Not all things need be predicted—a little fine surprise is fine indeed, in while.)