We investigate the possibility of measuring the phase angles in the Yukawa interaction of the 3rd generation quarks. The result can be used to discover new physics model. It is shown that the wrong-sign limit of the type-II two Higgs doublet model (2HDM), can be discovered at future Higgs factory even in the alignment limit. In the second part of the talk, I will share my resent experience of learning the "classic" axiomatic quantum field theory as a freshman.