Oz, in case you were unaware, is from Buffy. He was awesome. I hope you know Pheonix, but if not, she’s from X-Men.

CHONSP, once you say it, makes it pretty easy to remember the crucial elements for life.  The Han Solo system may work pretty well too.  Also, as a side note, Chlorine can be pretty important as well.  Who would’ve thought that what burns your eyes in a pool can be important to life?  Of course, there are a lot of other elements that are present in smaller amounts.