Our inaugural object is a well-loved, frequently-used tool here in the shop: the hot glue gun. Sometimes the most useful tools are ordinary and un-fancy. See also: screwdrivers, needle-nose pliers, masking tape.
Hot-melt glue is amazing stuff. Its ability to melt and ooze into the surface texture of a wide variety of materials means it can effectively bond adhesive-resistant stuff, such as polyethylene. Plastics, metals, wood, paper: no problem. You do need to be aware of how quickly it cools down; aluminum’s thermal conductivity can re-solidify the glue faster than you can squeeze your pieces together if you aren’t quick.
It’s also free of solvents, requires no mixing or curing or complicated steps, and is as easy to use as you remember from junior high. What more could you ask for?