Live and learn, most traders will lose their shirts and learn from their mistakes before becoming "successful" at trading for the long run.
If he thinks that it is not worth it to learn and stay with trading as he lose 40% then what's the deal with it? I know those people that are not giving up are the ones that are becoming successful in the end. But not all the time we as traders can't endure it the losses and mostly we will just give it up and just put our hands up.