  As in Greek mythology, the neutrino was born in the mind of Wolfgang Pauli to
salvage a fundamental principle. Its existence met with universal skepticism by
a scientific community used to infer particles from experiment. Its detection
in 1956 brought particle physics acceptance; its chirality explained maximal
parity violation in $\beta$ decay; its (apparent) masslessness led theorists to
imagine new symmetries. Neutrinos are pioneers of mutli-messenger astronomy,
from the Sun, from SNA1987, and now through IceCube's blazar. The discovery of
neutrino masses opened a new era in particle physics aswell as unexplored
windows on the universe. -Tiny neutrino masses suggest new physics at very
short distances through the Seesaw. - Neutrinos and quarks, unified by gauge
structure, display different mass and mixing patterns: small quark mixing
angles and two large neutrino mixing angles. This difference in mass and
mixings in the midst of gauge unification may be an important clue towards
Yukawa unification. - Neutrino mixings provide a new source of CP-violation,
and may solve the riddle of matter-antimatter asymmetry. We present a
historical journey of these "enfants terribles" of particle physics and their
importance in understanding our universe.
