Freudian slip

So there was this Freudian theory that somehow has gotten engrained in the consciousness of the people that a slip of the tongue is what you really wanted to say. This has always irritated me in the childhood, when I merely used to use the wrong diction and understand my mistake a nanosec later only to have people either scolding me or, infinitely more damningly, teasing me.
I always knew that the slip of the tongue is cause merely because of a silly mistake, and not because of a subconscious urge to say that instead.
Now a prof was teaching us about Freud and his contribution, and told use exactly why a slip of the tongue occurs. Freud was the fellow who came up with the term “slip of the tongue” which is known in psychological circles as the “Freudian slip”. Now according to Freud, there exists the conscious mind, the subconscious mind and the unconscious mind. The unconscious mind are the deep rooted desires, ideas and knowledge that takes a lot of will to surface. It is our underlying motives that are always hidden. The subconscious mind is kind of like the reflex mind, say someone asks your name and you know the answer without having to think about it. Now according to Freud there are many desires, specifically sexual hidden deep within out unconscious minds, and these show expression through dreams, activities like fidgeting with stuff, and slips of the tongue.
The prof, after relating all of this that the latest in psychology, in a journal released last year, claims that a slip of the tongue is just a careless mistake!
Maybe I will become a psychologist.
I think that the slip of the tongue takes place due to a mistaken subconscious. This occurs when your subconscious brain reacts faster than your conscious brain, and you say something else instead of what you were meant to say.