Glue This Wrench to the Bottom of the One With Which It Was Attached
When you need an allen wrench, you will never find one, which is why they come with almost every Ikea item. But years later, when you need to disassemble this TÄRENDÖ or even tighten a few bolts, it will disappear again.
Simple solution: attach it to the item in which it was included . Even if you have a good set of hex keys in your toolbox, it is convenient to know that you will have the right tool close at hand instead of running to the basement to find it. Bonus: there will be no more guilt about throwing away a perfectly good tool, even if you’re pretty sure you have a dozen of them … somewhere.