Heartbreak Waltz, TriArts, Inc., at the Chopin Theatre. The mantra of the older and wiser–“If I only knew then what I know now”–inspired playwright Barbara Carlisle to script and direct this fantasy piece. Fortysomething Louise communicates with her 17-year-old self, her purpose not to relive her youth but to reshape it by giving her young alter ego advice–things like “what matters in high school means squat in real life” and “sex is really, really good” (important information for a teenager growing up in the 1950s). Also involved are two women who know both Louises well: her flamboyant seductress mother Myrna (Patricia Austin) and friend Barbara (Vicki Riego de Dios), a homecoming queen turned jaded divorcee. Two men (Andrew Whatley and Owen Yen) represent Louise’s great loves.

Carlisle and cast infuse this clever concept with great energy and manage to wax nostalgic without getting too sappy. One sore point: no way could the lanky, sensitive Emily Kauffman have grown up (or shrunk) into Jenn Remke. This mismatch creates an unavoidable distraction in the scenes between the two women, made worse by the lack of chemistry between them. And costume designer Justine BonDurant has doubled up on frump to compensate for the fact that Remke is at least 20 years too young for the part. For this play to realize its potential, Carlisle needs to match the Louises better and tighten the draggy dialogue between them.