Yes,but...
I like to collect them from stores (advertising ones)
I like to keep the ones I received from contacts even quite long time ago.
Once blown and if not popped ... I keep them for another "session".
If they are wrinkled after deflation, they can be given a second life with heating via hot air from a hair dryer.
So ... keeping them beyond a year is not cool.
I just threw a shoe box full of rotten ones ... wasteful