Department of Physics2024-11-1020221742-658810.1088/1742-6596/2191/1/0120062-s2.0-85124958451http://dx.doi.org/10.1088/1742-6596/2191/1/012006https://hdl.handle.net/20.500.14288/17150In these expository notes, after a contemplation on the dawn of octonions, we give proofs for the Frobenius theorem and the Hurwitz theorem, we review the basics of Clifford algebras and spin groups, and exemplify the startling role played by the octonions in 7- A nd 8-dimensional phenomena such as the special 3- A nd 4-forms, the Bonan form, Spin(7) and Spin(8) groups and the mysterious triality. © 2021 Published under licence by IOP Publishing Ltd.MathematicsQuaternion algebraExceptional lie groupsConference proceedinghttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85124958451&doi=10.1088%2f1742-6596%2f2191%2f1%2f012006&partnerID=40&md5=2a84c39796690a5eeb4488962cff387c2101