I agree that it's not the only solution, but I still think some men/boys drive themselves crazy trying not to, and then slip up. And then they beat themselves up and feel like there is no hope or like they can't ever live worthily. I know this, because my boyfriend struggles with this. I don't think it is something that should keep someone out of the temple, from getting married, from going on a mission, as long as pornography or thoughts of vulgar type acts like rape aren't involved. Some boys have even done that since they were like five! In fact, I have heard many who have. I feel like it's just one of those natural things that, while not the best way to solve intimate feelings, it happens.
In many cases, many boys/men who feel like hope is lost and lose their confidence, fall into inactivity.... it's really upsetting to me as a year long member, seeing this kind of thing happen.