Most rookies are looking to take profits when the have a winning trade. Professionals look to continue riding the trend for all it's worth. As I've said here before, inexperienced traders need the boost to their self-esteem by posting smaller wins to validate their behavior as traders. Small or not, a win is a win and that's what's important to them. We advocate something that takes a little more evolution.
I have found in almost 30 years of teaching that a trader's unwillingness to add to winners is more of an uncomfortable, emotional problem than it is to understand the math involved.
Like any behavior, it takes some getting used to, but if you do it enough times, you can make it a good habit and replace the bad habit of having price targets.