For most of us, saving is something we do because we know we should. Perhaps it's because we want to retire. A better way to think of it, however, is purchasing time. The more money you save, the more you can buy your own time back.
As personal finance blog Save Money, Dammit points out, living month to month requires a certain threshold of money. If you don't have that amount of money, you have to work for it. Saving money allows you to buy your time back. Whether that comes in the form of a long break, or simply the freedom to quit your job before you find a new one, the more you save, the more you're "buying" your future time.
How long would it take for you to buy a month? In other words, how long would it take for you to save enough money to cover one month's expenses? The more you save, the more your time becomes available to you. While you can't buy more time, you can buy the ability to enjoy more of it.
By thinking of it this way, you can get a better handle on how to prioritise your savings. Putting aside an arbitrary amount based on your needs when you retire (which you can't know) can feel like guesswork. Saving money so that you can afford a month's worth of your time now is a lot more specific. You can give yourself a goal to work towards that's tangible and achievable, rather than abstract and off in the future.