Many people think an only child is lucky because of the material goods and attention he or she receives. But only children have their problems，too. For one thing，they have no privacy. Parents always feel entitled to know everything that's going on in an only child's life. Also，only children never have the opportunity to put the blame on a brother or sister for something they've done wrong. Third，only children miss the companionship of brothers and sisters. They can be lonely，and they may have trouble making friends later in life because they have never learned to get along with a brother or sister.