With money too, you can act "in advance" against a problem that hasn't happened yet - exactly like sunscreen that you put on before you go out into the sun, not after you get burned.
For example:The moment you get pocket money, before you buy anything - move part of it straight to savings. That way, when the temptation to buy something unplanned comes along, the money is already "protected" aside and isn't in your pocket at all.
The best protection for your savings is the kind that happens before the temptation even arrives.
You could also call this "paying yourself first": moving money to savings the moment you get it, before there's even a chance to spend it.
What do you think happens to money that stays in the regular account, compared to money that's already "locked away" in savings?