"No more zero days." The piece of self-help advice people can't stop sharing.

There are good days, meh days and bad days where even getting out of bed is a struggle. Maybe you’re feeling low, lost in work, relationships or life in general or just drowning in sadness for a reason you can’t quite explain.

Quite quickly, that “bad day” can turn into “bad days”, a “bad week”, a “bad month” or even a “bad year”. Clouded over, it can be hard to shake off or remember a day when you didn’t feel that way.

Firstly, you’re not alone. And secondly, Ryan from Canada has shared the self-help advice that may just cut through and make a difference.

He posted a lengthy comment on Reddit four years ago, in response to a question asked by another Reddit user. "I just don't care about myself," the poster began.

"I have lots of things I want to learn and do with my life, but I can't even bring myself to do what I'm required to do... I have no money, no one who really cares about me, shitty grades, shitty diet and exercise, and the worst part of it? It's not even that I hate any of this. I hate feeling like this, but not even enough to do something about it."

It struck a chord with many posters, but it was Ryan's response that really resonated, even resurfacing in a thread on the site yesterday. Many posters said they had saved, printed or shared his words and still use or read them everyday. His original comment has been liked over 10,000 times.

"My name’s Ryan and I live in Canada. Just moved to a new city for a dream job that I got because of the rules below. I owe a lot of my success to people much cooler, kinder, more loving and greater than me. When I get the chance to maybe let a little bit of help out, it’s a way of thanking them," he began.

Listen: Marian Keyes on what got her through depression. Post continues after audio.

His advice revolves around four simple rules.

1. Have as many 'Non Zero Days' as you can.
2. Be grateful to the three you's (Past, Present and Future you)
3. Forgive
4. Exercise and read books. (You get endorphins and exercise your mind)

The idea of Non Zero Days in particular is something everyone struggling with their mental health needs to know about.

"There are no more zero days. What's a zero day? A zero day is when you don't do a single f**king thing towards whatever dream or goal or want or whatever that you got going on. No more zeros," Ryan wrote.

"I'm not saying you gotta bust an essay out everyday, that's not the point. The point I'm trying to make is that you have to make yourself, promise yourself, that the new SYSTEM you live in is a NON-ZERO system. Didn't do anything all f**king day and it's 11:58 PM? Write one sentence. One pushup. Read one page of that chapter. One. Because one is non zero. You feel me?

"When you're in the super vortex of being bummed your pattern of behaviour is keeping the vortex going, that's what you're used to. Turning into productivity ultimate master of the universe doesn't happen from the vortex. It happens from a massive string of CONSISTENT NON ZEROS. That's rule number one. Do not forget."

As for rule two, while "being grateful to the three you's" may seem a little cheesy, Ryan argues (convincingly) that they're the basis of everything.

"Be GRATEFUL to the past you for the positive things you've done. And do favours for the future you like you would for your best bro. Feeling like shit today? Stop a second, think of a good decision you made yesterday. Salad and tuna instead of Big Mac? THANK YOU YOUNGER ME. Was yesterday a nonzero day because you wrote 200 words (hey, that's all you could muster)? THANK YOU YOUNGER ME," he wrote.

He then explains you treat future you like your best friend, doing things for them.

"Alarm clock goes off and bed is too comfy? Eff you present self, this one's for my best friend, the future me. I'm up and going for a 5 km run (or 25 meter run, it's gotta be non zero). MAKE SURE YOU THANK YOUR OLD SELF for rocking out at the end of every.single.thing. that makes your life better," he wrote.

"The cycle of doing something for someone else (future you) and thanking someone for the good in your life (past you) is key to building gratitude and productivity. Do not doubt me. Over time you should spread the gratitude to others who help you on your path."

For the full advice, read the original comment. And do a favour to all three you's and screenshot it, save it, bookmark it, print it or send it to a friend.