Why does the sentence "I love You" desperately seeks an answer?

Tweet

During our elementary years our English teacher taught us that among the kinds of sentences namely declarative, imperative, interrogative and exclamatory only the interrogative one requires or seeks for an answer. It can either be through Yes or No question or the Wh- one. Common among lovers, couples, friends exchanging this three little words, and it is impolite for you of you didn't even bother to respond back by saying "I Love You Too". Among lovers this three words is a very powerful one, that it can even take them into heaven or drag them into hell, and even worst it can break someones heart. But have you ever thought why this sentence desperately seeks for an answer while in the broadest sense it is not even a question?? Come to think of it...