In the 1960s, Tanzanian student Erasto Mpemba and his teacher published a paper with the title "Cool?" in this journal (Mpemba and Osborne 1969 "Phys. Educ." 4 172-5). They claimed that hot water freezes more quickly than cold water. The paper not only led to a wave of discussion, and more publications about this topic, but also to a whole series of new experiments, with the aim of verifying this apparent thermodynamic absurdity and finding an adequate explanation. Here we give a review with references to explanations and we offer some proposals for experimental student work in this area. We not only introduce the Mpemba effect as a paradoxical physics phenomenon, but also present a strong educational message that the Mpemba story brings to teachers and their students. This message also creates a bridge between this phenomenon and the discovery for which the 2011 Nobel Prize in Chemistry was awarded. It leads to critical adoption of traditional knowledge and encourages resilience in investigative exploration of new things. (Contains 2 figures.)