  Till 2010 we had three unknown parameters of neutrino oscillation: the third
mixing angle {\theta}_(13), the sign of the larger mass difference
{\Delta}m^(2)_(31) and the CP violating phase {\delta}. Thanks to a number of
consistent experimental results since then, culminating in the recent Daya Bay
reactor neutrino data, we have a definitive determination of {\theta}_(13) now.
Moreover its measured value, sin^(2)_(2 {\theta}_(13)) = 0.1, is close to its
earlier upper limit. This has promising implications for the determination of
the two remaining unknown parameters from the present and proposed accelerator
neutrino experiments in the foreseeable future. This article presents a
pedagogical review of these profound developments for the wider community of
young physicists including university students.
