artberniecareercarriercostcustomerdevelopdifficulteffectiveeffectivelyeffectivenesselanaeveryexperiencefinalefriedmangetgetshighimproveimprovementinsightsintelligencejamesleaderleadershiplearnlessonsleveragemagicmakemanagemanagermastermasteringneednhsofficeouttakespeopleperformanceperformingpowerreallyrobseasonservicesmithstatestrategiesstrengthssucceedsuccesssystemsteamteamstherapythinkingthriveunderstandingusewellbeingwilsonworkplace