In my early twenties i used to smoke and it was ok when I started, progressively paranoia and some real fcked up mental states set in, depression and such. I wans´t ok, eventually I started to avoid it like a real poison. Also gained some great mental awareness during these times, but it had a price.
Some time later, I smoked ocasionally and managed to control the bad effects and take some advantage of the good.
Nowadays when I have it smoke to a point where my body gets so used to it that it barely has an effect besides relaxing me.
Conclusion: weed just enhances whatever you are experiencing, if you are in a bad place, feeling depressed or insecure you´ll get that tenfold, if you are in a good place the same. Also you need some solid foundations where you stand (that goes for a lot of mind altering drugs) in order to control where it takes you.
So in answer to your question: yeah, I felt some really crazy thoughts, insecurity and paranoia. Just go easy man, see how you feel and dont try to take a step longer than your legs.