In your grandfather's day, it was all buy and sell, sell and buy. No god but the tape, and speculators and traders were its prophets. The business demanded open eyes, wits about you, and the assumption that even the silkiest cloud contained enemy fighters waiting to pounce. But there any real similarity ended. The amount of coolness and nerve required to stand firm in a market panic was a pale fraction of what it took to get through a minute of combat in the trenches or in the air.
Trading is like sex.
You don't have to be good at it to enjoy it. This is a trading floor. Trading is like no other profession I can think of other than dragon slaying. Facing that hot breath and those toothy jaws fearlessly, armed only with belief in oneself, on a daily basis. Like ancient mariners, traders wait for some bit of news to billow their financial sails and send them breezily on to a pleasing destination.