Fixing The Unfixable
Through believing in stories we make what is inherently fluid apparently fixed. And a great deal of our human suffering seems to come from this.
Intimate attractions
Joan Tollifson, in Bare-Bones Meditation, points this out in relation to our preferences for intimate relationships. Of course, we cannot know who we will be attracted to next. It is a mystery, as the rest of our life. And still, we put a label on ourselves and others which makes this seem much more explained and fixed than it really is.
Belief, values and imposing it on others
Beyond this, we may believe in the label, ignoring the mystery and unpredictability of life. So when life shows up in a different way than what the label predicts, there is confusion, struggle and possibly suffering.
We also may add value judgments to these labels. We may see heterosexuality as "better" than the other options (allows for procreation, aligned with particular interpretations of some religions). Others see bisexuality as "better" (more options and more fluid), and so on. And this only increases the suffering when life shows up otherwise.
And beyond all this, we may not only apply it to our own life -stifling it, but also to other people's lives - trying to stifle theirs. And this is another way to enhance suffering.
Suffering from what is beyond the label
The label itself is harmless. It is only a label, a temporary abstraction added to a temporary phenomena. The suffering comes when we belive in the label and life shows up differently, when we add value judgments to the labels, and - maybe especially so - when we try to have others conform to our own idiosyncratic stories.