A person could easily get lost in the land of idioms and etymology. If three is supposed to be so lucky, I definitely wasted time searching our suburban backyard for a four leaf clover when I was a kid. 

My nuclear family is made up of three. (I love that phrase. Nuclear, as in atomic, which is what I thought it meant the first time I ever heard it and it made sense.) Good things come in three. If you're inclined to think bad things come in three, perhaps you could also think, "What a relief, just three!" It's manageable. Three has a hold on me, I've noticed. 

This year my friend Becky Blake won the CBC Short Story Prize for her brilliant writing, a story titled The Three Times Rule. I'm sure I would have loved it even if it didn't tripwire my random triplet-inspired thoughts.