Lewis Pugh, an ocean advocate who has swum in icy oceans and turbulent seas, knows about endurance and the elasticity of time. In a podcast late last year he spoke about the challenge of long-distance swims, and when I heard his words last week they resonated powerfully.
''The thing about long-distance swimming is how the goalposts can shift,'' he said. ''You think you're going to do a 10-hour swim and then you get to the coast of France and suddenly a current picks you up and it's going to be a 15-hour swim. You think it's going to be 15 hours and suddenly it's 20 hours.
''It can break your mind. And so you have to be able to have that resilience when the goalposts shift. Because they will shift. And they never shift in the direction you want them to shift. To keep on going, to put one arm in front of the next and to recalibrate yourself.''
In a way it's what we have been doing for 100 days, watching lockdowns extend and recalibrating our lives. We flinch from the phrase ''flattening the curve'' and live according to a curious calendar. We think not in months or seasons, but in circuit breakers. Spring is passing us by and we barely care because we're busy excavating a grit we never knew we had.
A hundred days is just a marker of how far we've come, a signpost, but it's not a promise of anything. We don't know if this is halfway to normality, or far away, because this virus doesn't just sicken and kill, it teases and shifts our goalposts. Like Pugh in the water, we must endure.
We're caught in the midst of a stranded planet with its empty streets which resemble abandoned film sets. Faith is being tested and human conceit is being punctured. For all our bragging about forecasts and algorithms, this virus has humbled us. We can't read the future, but we wish to exit the present. We're watching the corner of the TV screen and wishing the callous calculator that's measuring human lives lost - 224,708, 224,709 - would just, please, stop.
We're a species not in control, and it's strange and a trifle scary. We wish for things we never did before, like the simple pleasure of the noisy, lively street. We might smell a little better - all that soap - and because of masks we tend to look each other in the eye.
We're living a sort of tentative life where everything is provisional. Once it's over, you wonder, will men forget about mops and might parents lose their current veneration of teachers? We call nurses heroes now, as if they aren't on a normal, daily basis, and we've forgotten the touch of a mother's wrinkled hand on our faces. We're reordering our priorities and nod in amused assent when people tweet that bookshops must be kept open. They are, some argue, an essential service.
We've never been so devoted to science - antibodies, vaccines - nor been so drawn to the arts. From one we seek information, from the other solace. People are filling journals with reflection, digging out recipes from old aunts, growing life in veranda pots and watching Shakespeare plays on the Internet. A friend sends me two poems, one titled ''The Last Today'' and the other ''The First Tomorrow''.
We're divided by distance and looking for anything (Zoom) or anyone (riders) that can help bridge it. Cartoonist Christopher Weyant, a contributor to The New Yorker, draws a large Trojan horse on a drawbridge, with sentries looking on from the ramparts of a fort and saying: ''Who cares what it is. I'm happy we still get delivery.''
We're amending our understanding of space - how little some people have, how much we miss openness - and hopefully appreciating the idea of separation. The temporary partitioning of families that we agonise over now - maybe your kids are abroad or your parents are in another suburb - is the normal life, year after year, of the foreign worker and the maid.
Only in glib terms is this virus an equal opportunity thug, for if you look around the globe it's always the poor - out of a job, standing in food lines, uninsured - who suffer most. Reporters and photographers are brilliantly documenting forlorn cities but very few go to the villages and interiors. There is a grief out there which we must only imagine.
Little things have slipped out of our reach like a child's toy in a sudden flood. A daughter's graduation has passed, a marriage postponed (a friend's niece told her, what is a wedding absent of hugs), a job offer now withdrawn, a tournament cancelled. For some this may seem trivial in the face of the larger chaos, but it isn't, for it tells us how this virus has rearranged our lives.
So what have we done for 100 days? We've sulked, moped, worried, but we've also reached for one another, for faith, for routine, for laughter. We've improvised, like the softballer who bench-presses her sofa. We've found our own sweet discipline, like my friend's wife, a banker, who dresses as elegantly as she would for office even though she is working from home.
Mostly we hang on to hope, a slim thread with unusual tensile strength. We look for it in photos, cartoons, tweets, stories. We see it in the landlord who waives a few months of rent and find it in the kindness of the volunteer who distributes food to the less fortunate.
In India, a young man - as the Hindustan Times marvellously recounted - cycles 1,700km interstate, armed with no phone and no map, to get home. In America, a man takes his newborn child to his parents' place and they stand, one group on the street, the other in a doorway, and love reaches across space and generations.
There is no such thing as victory over the virus because the suffering left in its wake will linger for long, but we must meet it like that old soldier Captain Tom Moore.
He wanted to raise £1,000 (S$1,800) for Britain's National Health Service by completing 100 laps of his garden before his 100th birthday, but eventually raised over £32 million. His story appeals to us because his act tells us of the things we're capable of as humans: willpower, empathy, generosity and modesty.
The virus will keep challenging us and pushing us, and we will need to adapt and invent and dig for answers. Inspiration comes to us all from various places and for me some of it arrives from a piece of paper, yellowed with age and torn, which was stuck to my father's ugly steel cupboard for over 25 years.
On it was scribbled an old Albert Camus quote and it read: ''In the depths of winter, I finally learned that there lay within me an invincible summer.''
Every time I think of it, I feel the pull of hope.