That adage, out of sight, out of mind, can be as much an admonishment as a recognition that something once pressing may have receded from the frontline of public consciousness.
Once a storm has passed we are so relieved to have endured we worry about flood barriers another day.
A little over a decade ago this country was in the grip of something close enough to an epidemic of suicide.
Tragedy came almost daily and cut especially deep when young people, sometimes very young people, were lost. That pain was even sharper when one calamity sparked a series of copycat deaths.
Families were shattered then communities were devastated. For those scarred by those agonies they can never be out of sight or out of mind but it may just be that the issue is not as central as it was because the suicide rate is at its lowest level this century.
Provisional figures from the National Office for Suicide Prevention show there were 352 suicides last year, 282 male and 70 female or 7.2 per 100,000 of population.
This is more than 100 fewer than in 2017 when 392, 312 male and 80 female, representing 8.2 of 100,000 population, died by suicide.
Today’s figures are edging towards half the peak rate recorded in 2001 with 13.5 suicides per 100,000.
Three years later, a Celtic Tiger year when economic growth hit 4.6%, the rate remained at 12.2, a figure that has not been exceeded.
This welcome trend is consistent and though suicide still ends far too many lives we should consider why the rate has almost halved since 2001.
That men outnumber women by four-to-one in these figures raises questions too.
Education, evolving emotional awareness and communications skills, a deeper, more genuine empathy and, possibly most of all, new levels of inclusion and tolerance offer a positive perspective on the social shift that cut suicide figures.
The conscious effort to de-shame mental illness, to see it as just another of life’s natural, endurable travails rather than a taboo was hugely significant too. Economic rejuvenation had an impact even if that great achievement is diluted by the housing crisis.
That many people, some very prominent figures among them, had to modify their position once one of their children announced they were not heterosexual was hugely significant.
Taoiseach Leo Varadkar’s openness, an openness not entirely without risk, should not be underestimated either.
The marriage equality and abortion referendums are the high points of a changing society but every now and then a series of events, small in themselves, remind us of the kind of excluding, our-way-or-the-highway belief systems that contributed to peak suicide rates — and that living suicide, despair-driven alcoholism too.
The decision by the pastor at a Nashville Catholic school last week to ban the Harry Potter books over “actual curses and spells” seems one.
The visceral opposition of former DUP health minister Jim Wells to a same-sex couple featuring on Strictly Come Dancing seems another.
This week’s visit by Vice President Mike Pence was reminder of how enduring and well-positioned fundamentalism can be.
Pence, an adherent of the “Graham rule” which means he will not stay alone in a room with a woman who is not his wife lest the temptations of the flesh undo him — or her — is the polar opposite to our head of state and our leader of Government.
Happy to exploit his “Irishness” Pence clings to beliefs anathema to the majority of Irish people. We can be proud that Michael D Higgins and Leo Varadkar represent today’s Ireland in a way that recognises the duty to overcome old hatreds, old cruelties.
That suicide rates are falling because of this inclusiveness cannot be seen in any way other than a victory for civilised, tolerant and necessary change.
Which raises a sad, unavoidable question — how many lost and wasted lives might have blossomed and enriched our world had we discovered tolerance and humanity generations ago.