Being suscpicious of someone is secretly addictive, not forgetting unhealthy and bad for your relationship with that person. Most importantly, it is bad for yourself. It will be tough on you to function normally and freely if you have suspicions in your head. And yes, most times, it is just in your head. This is not about being blindly optimistic. Sometimes in life, things happen, but it is no reason for you to be overly cautious. If it really is bothering you, address it in the beginning. Do not let the snake turn into an anaconda before you could finally not take it any longer and come face to face with it. By that time, situations usually turn out for the worst. So do not let those spy and detective shows make you think that you could also try out those slick looking things they do in your real life. You might just end up hurt real bad.