The SU(3) quark model encounters a great challenge in describing even-parity scalar mesons. Specifically, the two-quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and the charmonium-like state X(3872). A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this talk, I'll focus on the near mass degeneracy of scalar charmed mesons and discuss its implications on B physics.