I can't believe anyone would tell a person to throw way all there thread if it was from another project and buy new. That person must be related to some of the Chef, that tell you to throw away all you old spices. I have had spices for years and haven't had a problem with them, nor have I had problem with thread. There are some thread that have given me problems, and If I find that I do throw them. I had a lot of thread between regular thread and embroidery type and with what threads cost, it is just to expensive to replace all of them.