The story starts as it usually does: physicists to their thing and mathematician try to make sense of whatever that is. Here, Topological Quantum Field Theories (TQFTs) model the quantum universe when absolutely nothing happens locally (interesting isn't it?). But there is a twist: the mathematical model is so nice that mathematicians start playing with it just for fun. Plus, it is a rare pleasure to be able to make conjectures based on physical motivations. I will explain what TQFTs model and why they are interesting in physics, and give a few examples of physical insights that gave rise to interesting new mathematics.