Any tradesman will advise while on a ladder, never step back to admire your work. It's something the Coalition might bear in mind as it signs off on a high-wire act to reopen schools.
As Irish National Teachers Organisation general secretary John Boyle put it: "There will be a lot of pressure on boards of management and principals to deliver the return to school plans and it is a very big ask."
Accommodating vital new protection protocols in a classroom, and enforcing urgent safety strictures that seem to go against every instinct of bringing people together, must from now on be hard-wired into the system.
According to the writer William D Tammeus: "You don't really understand human nature unless you know why a child on a merry-go-round will wave at his parents every time around - and why his parents will always wave back."
It's a level of concern that never rests, a level which like everything else has soared to new heights over the past six months.
So it makes complete sense for Taoiseach Micheál Martin to list keeping pupils, teachers, and staff safe as a singular prerogative for the Government.
And it is an onerous responsibility. How onerous is reflected in the fact there are one million children and over 4,000 primary and secondary schools to be taken into consideration.
True, primary schools may not impose physical distancing rules on the youngest classes.
But for older classes, and second-level schools, teachers and pupils will be asked to keep at least one metre apart.
Unions have pointed out national supply panels of teachers will be essential to keeping schools open.
The €400m earmarked for the return is welcome as the demand for resources will be unprecedented. But as once noted by Franklin D Roosevelt: "The school is the last expenditure upon which we should be willing to economise."
Additional guidance counsellors and psychologists will doubtlessly be required to be available to schools to help students adapt to the new unfamiliar environment.
It has been said to bring up a child in the way he or she should go, it is worth travelling that way yourself, once in a while. But no pupil, parent or teacher has ever been asked to traverse the terrain Covid-19 has led us into.
Association of Secondary Teachers in Ireland general secretary Kieran Christie said that while teachers will work with the Government, it is essential the health of both students and staff is fully protected.
The message was brought home by the fact the WHO has just declared Covid-19 is "easily the most severe" global health emergency the organisation has ever encountered.
The statement came as the global number of confirmed Covid-19 cases passed 16 million.
We know how grimly predictable the virus is. Its ruthlessly efficient, and won't change its behaviour: so we simply must change ours.