De-ionised water does have a shelf life - DI water is, by its very nature and name, very low in ions and hungry for them. In time it will leach ions from the container and atmosphere, when exposed to it, and so becomes less and less de-ionized as time goes on. In reagent grade chemistry it may interfere with the result of a subtle and sensitive experiment but probably not be detrimental in garage use, although ten years is a while!