隠れる: to hide. I think of the left radical as a butt...
The goats meme: an image to hide from
Using this knowledge, turn the kanji into a picture with your imagination and bam!: horrible mnemonic that is stuck with me forever, just like the original image.
If you don't get this post, trust me, you don't want to. Don't google it.
Other bad mnemonics:
皮膚= HI (he) has FUgly skin.
床= YU KAn't park a tree on my floor.
芝生=SHE BUfFUs up the lawn.