Fantasizing has to do with processing various thoughts in your mind. These thoughts are most times played out at your will. For example, you could fantasize to be a celebrity who is well known, and would always be applauded whenever you walk around. This fantasy could play out continuously in your thoughts, and you might end up being positively motivated to chase that dream. In other cases, when you discover that it is almost impossible for you to achieve this, you could be driven to carry out acts which can be regarded as dangerous and nefarious all because you want an acclaimed name for yourself.
Fantasizing becomes an unhealthy thought pattern when these thoughts which go on in your head remain for a long time without materializing into something productive. This could make someone lose it totally and resort to other quicker but dangerous methods. Also, in a case where one fantasizes being like a particular celebrity, it might get so bad that such person could goes to unimaginable lengths to ensure that he or she would be seen in that same light.
Also, another unhealthy thought pattern for fantasizing, is replacing friendships and relationships made in reality, with imaginations. One mistake people always make is, they spend hours fantasizing about having the right set of friends who they can always spend quality time with and with whom they can always trust wholeheartedly. Well in reality, friends like that do not exist, no one is totally infallible as we all have shortcomings which are bound to showcase themselves at any point in time.
The best thing which can be done in this case, is learning to meet people. It could start with asking for their names, then their hobbies could follow and from there, you would be surprised to discover that you are on your way to building long-lasting relationships. So, it is important that inasmuch as we may love to fantasize, we should be careful of not allowing these fantasies take over from reality. Unhealthy thoughts patterns are what give rise to addictions, and addictions could lead to various occurrences which would ultimately lead to death.
Major factors which aid fantasizing such as movies, social media, books and the likes, should be avoided if they are starting to replace the essence of reality in our lives.