Take my word for it. That sentence will be a far better companion to you in times of storm and cloud than any of the mantras the internet is full of.
We all understand what the simple sentence is aiming at — that we have to defer gratification and bear frustration before a good outcome occurs.
But I want to add two twists to it.
One. After it is bad, nobody promises you it will be good.
At most, the chance of things being better will rise.
There are no guarantees of happiness in this world. None. In fact, weaning yourself off the expectation of guaranteed happiness will genuinely make you happier.
Two. The tragedy of this era is that we have reversed the order.
We first want to be promised the good, and then we are willing to deal with the bad. Perhaps.
There is just one tiny problem with that: reality does not work that way.
Are you nodding in agreement? Then why does everybody continue to insist idiotically on a click and a match on a first date?
Notice what the reversal costs. If you require the promise first, you will only ever undertake things whose outcome was already visible — which is a precise description of a life in which nothing much happens.
So embrace the difficulty knocking at your door.
It may not be pleasant. But you can manage it, and managing it is the only route by which a person acquires the evidence that they can.