Please note that the subtitle of I'm Too Young to Be Seventy is And Other Delusions. Yes, Judith Viorst is well aware that she's a septuagenarian, and in her hilarious and poignant new collection she has written a stellar set of poems to . . . celebrate? Commiserate? Whatever her motivation, Viorst's verses are whip-smart and will ring true to anyone entering this decade of their lives. (A noted children's book author whose latest volume for kids is reviewed elsewhere in this issue, Viorst also wrote collections to acknowledge her 40s, 50s and 60s.) In one of the funniest pieces, Viorst firmly insists that her middle-aged children still need her advice even though it's now about periodontal disease and tax-free bonds. In one of the sweetest, she writes, Still married after all these years? / No mystery. / We are each other's habit, / and each other's history. Readers don't need to be anywhere near 70 to appreciate such sentiments.