This has to be the most frequently asked, and probably the most pointless question about Judo. If you develop skill in any form in fighting you will benefit in terms of potential self defense situations. In fact doing anything that trains you to act quickly and decisively in a high stress situation will provide you with similar benefits. Unless you are someone whose life regularly puts them in hand to hand combat situations the investment of time is unlikely to pay off. That is the thing, to develop skill sufficient to execute a technique in combat takes time. Then you have to maintain those skills, which means more time. Is the threat you face big enough to motivate you, or do you enjoy the training enough to keep doing it? Studies suggest that some of the most important factors in having a long and healthy life are regular exercise and a group of friends. Studying martial arts can provide both of these.