Harsh life or happiness?

Here are two kanji that are easily confused:

辛　　SHIN kara(i) tsura(i) = harsh
This can mean a (relatively) harsh taste (spicy = karai, salty = shiokarai), or a harsh experience ( tsurai = hard or painful, 心労 or shinrou = toil, 世知辛い or sechikarai is used to describe a hard life or a cruel world).

幸　KOU saiwa(i) sachi shiawa(se) = happiness, luck
This can mean happiness ( 幸福 or koufuku,　幸せ or shiawase) or it can mean good fortune and blessings (幸運 or kouun, 幸い or saiwai). And often both (幸 or sachi means happiness and good fortune).

There's only one stroke that makes these two kanji distinct. So here's your mnemonic:

The harshest of （辛い） experiences can be transformed into happiness (幸福) by a single stroke of good fortune (幸運 ).