Fred... my good man...
However, casting aspersions as to what Dan can/can't do or whether what he "teaches" is/is not worthless... is completely unnecessary, if not ungentlemanly.
That is why I used what is essentially an "If a then b."
"If Jake goes walking in a bad neighborhood at night with $100 he just took out of the ATM in his hand, then somebody is going to try to take it from him."
Jake may very well be able to kick the sorry ass of anyone who tries, and the statement of the inevitable is not an endorsement of the attempt to take it.
"It's very likely that the reason Jake doesn't go walking in bad neighborhoods with a wad of cash in his hand is that the time and effort involved in defending himself against the inevitable robbery attempt and subsequently justifying his actions to the police really makes it an energy sink that he would just as soon avoid."
Unlike the hypothetical Jake, I've met Dan, and really don't want to think about what would happen if he inadvertently ended up in the wrong part of town facing a knucklehead who thought he had found himself an easy mark walking away from an ATM machine.
Like all analogies, this is imperfect and falls apart if you try to push it too far or nail it down too tightly, but anyone who isn't simply looking for an argument should get my drift.