The Home Forum essay "Shakespeare on the Wall," Sept. 5, sheds much insight into the elusive subject of poetry. Poetry is probably the most controversial form of literature. To many people it is, by turns, confusing, pretentious, obscure, unrealistic, etc. But in the last analysis, poetry mirrors our lives and emotions in a way that is unique.A great poem speaks to us personally, just as a great painting does, or a sublime symphony. All three are closely related. They are curiously and wonderfully interwoven. William Beyer, Belvidere, Ill. Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.