When I'm checking out lifehacks, my reaction comes in two stages:
Part one: Wow, that's cool! I'll definitely use that! Part two: That's really simple, and I'm really dumb for not utilizing it sooner.
Really though, it's best not to beat ourselves up for not thinking of this stuff earlier. Instead, we can use it to make our lives a little bit easier, and maybe feel a little bit smarter in the process.