The CRT acts like a capacitor, storing charge for quite considerable lengths of time. Consider that a B&W would typically run 10kV to 15kV, and color sets easily 25kV, and that should give you some idea of how much energy one of those things can hold. And with those kinds of voltages, you don't even need to make contact to find you've become a discharge path, that stuff will reach out and grab you across considerable air gaps.

oh, boy. the temptations of telling how to find out on your own are strong!

the capacitors in CRTs could store a charge for a long time. i've seen people that assumed the caps were discharged find out the hard way when they shorted the leads with a tool. the noise alone is enough to make one need clean shorts. the only good thing is that they discharge quickly, but they give you "both barrels" worth to borrow a phrase.

The CRT retains a high voltage charge even when the TV is unplugged.

CRTs hold a deadly charge for minutes to hours after being unplugged. CRTs can also emit x-rays if you bypass safety circuits. And touching a live flyback would be shaking hands with death. They were also manufactured before RoHS, so don't lick the PCBs or throw them in the ocean. Other than that, they're perfectly safe.