From the rusty hardware parts department of WTF

Many years ago I got tired of dumping a 5 gal bucket of bolts out to find what I needed so I took a bunch of 2 1/2 gallon buckets and started one for 1/4", 5/16", 3/8", 7/16' and larger. And one for lug nuts. Made my life a lot easier.
4 foot by 8 foot shelf full of 4” square pigeon holes. Im scared its going to fall off the wall.