does anybody find it easy to talk if they don't think about the words beforehand?

does anybody find it easy to talk if they don't think about the words beforehand? Let me try to explain. It seems like if I have a planned sentence or have thought about words in advance of a conversation I will most likely get a block when try to say them. It seems I block way less if I am caught off guard and let my mouth just say the words instead of thinking about them?