"Checking your smartphone at night can cause BLINDNESS," it began as I squinted at the WhatsApp message which glowed, apparently dangerously, in the dark.
The missive was from an acquaintance in one of several mass WhatsApp groups I am in.
Parts of my life are now measured out in such messaging app chats, each typically involving scores of participants.
Sorted into tribes such as fellow parents, ex-schoolmates and volunteer groups, I've learnt to mute mass WhatsApp chats, with their occasional 30-text-strong flurries of news breaks, replies and rebuttals.
WhatsApp groups are usually assembled for a higher administrative purpose, such as organising gatherings and transmitting pertinent information.
But group chats are not strictly functional. Anxious to get everyone on board, some of my WhatsApp colleagues repeat information in mass e-mails and individual texts to laggards.
Being in large WhatsApp groups often simply illustrates FOMO (fear of missing out).
As one friend put it: "I want to know what's happening, but not too much."
Sure, I want to keep abreast of unexpected developments, such as impromptu invites for coffee, and gossip, which can spring up delightfully amid unpromising discussions about meeting times.
I wish, for instance, that I'd been a cyber fly on the wall at a mass chat where, another friend once told me, a parent said she hoped her child's class could retake their class photos because her child's hair didn't look nice.
Yet, despite such enlivening moments, mass WhatsApp chats can be fraught with tedium and social conformity.
One man's spam is another man's Public Service Announcement.
Live and let live, I mutter to myself as I delete group-chat texts exhorting me to beware of kidnap scams, to consider how a flower is shaped like an angel or to tell others about various cancer- defeating fruit.
Protracted "thank yous" - to you and you and you - and pointless "okays" (what does one really mean by "okay"? ) also get to me.
So, you ask reasonably, why don't I simply quit all mass WhatsApp groups?
There are several reasons, such as cowardice.
I admire what I cannot achieve: A decisive exit from a ponderous group chat, where "L left" is the only notification the app gives users when group member L leaves.
Owing to my conformist urge to get along, I don't want to hurt anyone's feelings.
It is not only me.
WhatsApp group administrators, who determine who can join the chat by adding people's phone numbers, sometimes gently suggest that, in general, it might perhaps be helpful if everyone only sends texts relating to the group's activities. If everybody doesn't mind, of course.
Inevitably, this softly-softly approach manages to offend the spamming few, who indignantly protest that they are sharing their knowledge and what's wrong with that?
To which there is no non-inflammatory answer, so the status quo is maintained.
I also want to feel useful.
For example, I am grateful for messages clarifying when my son's next tingxie (Chinese spelling) is, when I lose track of test dates.
I was chuffed on the rare occasion when I could e-shout: "Yes! I took notes at the parent-teacher meeting, please have them!" (Such are the thrills of parenthood.)
Last of all, I should confess to a little light spamming.
"Happy Birthday! (insert unfashionable cake/beer/ kiss-blowing emoji)" I text to the group, adding to a pile of similarly unoriginal greetings.
Part of it is social pressure to not stick out in silent abstinence. But the birthday boy seems glad. This helps explain both the aggravations of mass WhatsApp groups and their consolations.
We grant our friends more latitude than acquaintances and strangers, and mass chat groups tend to be a mix of these.
While I dismiss my friend's desire to add ever more strangers to a 70-member WhatsApp group as a tic of exuberance, I am less enthused with innocent acquaintances mulling over what to order for dinner.
The chatterers in any WhatsApp group seem happy talking to their friends, though the silent majority may be aggrieved at what appears to be an interminable exchange.
So, in the immortal lyrics of The Clash, should I stay or should I go?
I'm staying for now. After all, I'll probably be sending Merry Christmas wishes on WhatsApp soon.
A version of this article appeared in the print edition of The Sunday Times on November 06, 2016, with the headline 'WhatsApp, WhatsDown'. Print Edition | Subscribe
We have been experiencing some problems with subscriber log-ins and apologise for the inconvenience caused. Until we resolve the issues, subscribers need not log in to access ST Digital articles. But a log-in is still required for our PDFs.