Wiktionary
vb. (context idiomatic English) To opt for a difficult course of action when a simpler or safer alternative is available; to make an unwise decision against sound advice.
Usage examples of "swim upstream".
It seemed hardly possible that any fish bigger than a minnow could swim upstream through this obstacle.
We don't know what prompted her to swim upstream now, now when so many other Camelot species are changing their habits.
He created wheeled eyes to run along the riverbank, and other little eyes to swim upstream in the Floh, and still others to fly over the wall, into the unknown lands.
We had to swim upstream, so to speak, but it didn't look like anyone was bothering to look at us.
You otters, swim upstream and see if you can sight the searat ship coming this way.
And in case I seem to have claimed some premature wisdom on the subject of racial relations, let me say that the little I've done to swim upstream against the current of blind white fear doesn't amount to so much as a single handful of dry dust thrown on those wild waters.
Ben pushed his opponent away, and let himself plummet as deep as the river would take him, trying to swim upstream.
It would be like trying to swim upstream against a strong current.
Inside my mother, a billion sperm swim upstream, males in the lead.
But when we were working on separating the gases in the air, to make those special masks so that you could swim upstream into the City, we also found how to make gases that are lighter than the air.