Very very sad.
Similarly, it's also a good idea to make sure you label things every time you make a solution of something, even if it's just salt.
When I get in a rush or focused on a project, I'll often forget to label containers, thinking to myself, "I'll remember what it is". My husband (with his chemistry and culinary backgrounds) is very sensitive to containers of unlabeled, mystery stuff in the house. So it's good...he keeps me on track and (mostly) labeling my stuff when I mix up a solution of something.
So, label your stuff every time it comes out of the original container into another. If you mix up a solution of something (i.e. levamisole) put the final concentration on the bottle, too. Personally, I also often write on the bottle how I made it (mostly for me so I can make it again). If I buy something in bulk, I spend the extra little bit to also get a small container of it (for example, Safe, Excel, Melafix...) so that I can aliquot my working stock into a properly labeled container and just refill that from the big bottle every time it runs out. This way everyone in the house knows exactly what's in a container. always.