Did you think that savings in the form of money are essentially just a promise from other people to give you something you want in the future for the good things you do now or did in the past? And, as with any promise, it's based on some kind of social contract. And, as with any contract, it requires some punishment mechanism in case of violation of contract terms. And, traditionally, institutes like governments, courts, judges, churches were used to implement this. In the case of Bitcoin though, this promise is based on the belief of many people that Bitcoin will grow in price perpetually (or, stay at the same value at least). And if, for some reason like a bug in software, targeted attack, or invention of some kind of better cryptocurrency, enough people will lose this belief - you will lose these promises too. My point is that Bitcoin is a great invention, but its natural purpose is a payment means, not a saving means. It's just a temporary but pleasant side-effect that you can effectively store value using Bitcoin now. As for long-term and reliable savings, I think it's better to use something based not on a belief but on a natural demand, like commodities, businesses, and education.