The model of a pure spin 1/2, detached from all other degrees of freedom of a particle, is one of the simplest in quantum mechanics. Yet, it defies our intuition and resists developing that pleasant sensation of being able to relate a new concept to something that we think we already know (or at least are used to thinking about). We call this feeling “intuitive understanding,” and it does play an important albeit mysterious role in our ability to use new concepts. The reason for this difficulty, of course, lies in the fact that spin is a purely quantum phenomenon with no reasonable way to model it on something that we know from classical physics. While the only known to me bulletproof remedy for this predicament is practice, I will try to somehow ease your pain by taking the time to develop the concept of spin and by providing empirical and theoretical arguments for its inevitability.