Even some useless stuff would be of use some day

Question

Is there any common idiom or expression in English which can convey such a message that: anything that is of no use, will be used someday for sure. It is a translated proverb which believes do not underestimate some out-of-use things. It indicates the message that you have to value your belongings and not through everything away.

The only idiom I know in English is:

• Keep it seven years and you'll find a use for it;

But for me, there is something missing in this idiom which is hard to explain. So I think it wouldnt work in this sense. (If you think it works please let me know.)

Note: it's not at all about hoarders who don't have the heart to throw away even useless stuff.

Answer 1

Something that is very close to this sentiment—although being a proverb, it's not identical—is every dog has its day:

[The Free Dictionary]

Prov. Everyone gets a chance eventually. Don't worry, you'll get chosen for the team. Every dog has its day. You may become famous someday. Every dog has his day.

Although, if interpreted in its usual sense it's talking about people eventually getting a chance, it's still a metaphor, and it would be easily understood in context:

"This is a useless piece of junk."
"Keep it around—it may come in handy sometime. Every dog has its day."

Answer 2

I have commonly heard:

One man's trash is another man's treasure.

It doesn't have the exact same meaning, but it is similar to what you are looking for. Even if you do not have a use for something, it may have a use to other people. It can therefore also mean that even if you don't obviously have a use for something now, it does not mean that it is literally useless, nor does it mean that you won't have a use for it in the future.

I have never heard the "Keep it seven years" idiom.

There's also a common statement that just says the exact thing you're looking for, but it's not a proverb or saying:

Well, hold onto it; you might find a use for it one day.