There are certain scents, sounds, and images that prompt memories seemingly buried in the back of the mind long ago. One such positive nostalgic trigger is springtime lilacs in bloom.

When I was little, my mother taught at the Moscow State University and often brought me there. The University's grounds include beautiful parks and awe-inspiring Stalinist architecture surging toward the sky. Her professional holiday, Chemist's Day, has been celebrated in May for as long as I remember. And that, of course, is when all those deliciously scented and gently colored lilacs are in bloom.

One Russian tradition says that if you find a five-leaf lilac flower, unlike the typical four-leaf exemplars, you should eat it and make a wish. I suppose it's akin to the luck of a four-leaf clover in Celtic culture. For a child that I once was, the search was particularly exciting. I've made dozens of wishes that way. Even though I can't recall any of them coming true, I still look for five-leaf lilacs on occasion.

Just in case.