Absolutely, you just never know when something you bought a million years ago is just perfect for what you need.
I have a habit of buying things and pulling them apart to use them a different way as well, for example I bought a sheet of sticky back disco ball glass that is one solid sheet, but if I run my craft knife between all the cuts in the glass, I now have a million little glass mirror squares to stick on cards in chequer patterns or little rows of diamonds. Those have already been used on quite a few cards for some added bling. That reminds me to go and raid mum's huge box of buttons. I haven't used buttons on cards before but the idea excites me.