First, let's define what exactly is meant by living someone else's life. As a rule, it is a profound part in the life of a loved one, adoption for him the important decisions, ongoing support, and assistance in solving problems. It would seem, nothing wrong with that. But in fact, this way of acting leads to two unpleasant effects. First, your subject loses the ability to independence, and secondly, you are wasting your is not infinite time, not for themselves but for someone else. Of course, this is the easiest way to solve human problems, to whose fate you care, but not the most correct.
Start living someone else's life just. Several times put their interests below other people, and you're done! Discard important meeting for therapeutic conversations being sad with a friend, take a vacation to help a friend with a repair, will atrocites work and help to ex-girlfriend move a couch - the options are many, but the result is the same. You will begin to experience genuine pleasure even from someone else's gratitude, and awareness of the nobleness and beauty of their actions. The trouble is that by so doing you will probably destroy your own life, career, plans.
Learn to refuse. To say "no" initially very difficult, but to learn this you must. Remember, how much of your time you spent on the problems of others, not because you needed it, but simply because of the inability to say no. As a rule, active participation in other people's lives is associated with low self-esteem, the need depending on you. If this is true in your case, try to find other ways to improve your beliefs about yourself. For example, make a successful career, win the contest, write a book - in General, do something for yourself.
By the way, self-improvement, paradoxically, is the best way not only to live his own life, but to help others. Give them the opportunity to realize that you're no different, and in their power to achieve the same success as you. Perhaps they will turn to you for advice, but this is another aid: not a pointless part in the unsuccessful cases, and support on ways to improve. In order to be able to help and advise, you have to be better than those whom we help. More successful, wealthier, more educated, and happier, because otherwise it does not help, and a crime against ourselves.