As a former semi driver and still current CDL-A holder, I would like to say the parent was exactly right and your attitude is not helpful. Truck drivers do absolutely have a duty to drive responsibly and not put others in harms way. Too many drivers out there take what happens on the road personally. Take the emotion out of it. I know that can be hard to do, but it is necessary for your safety and sanity if you are going to be driving 8+ hours a day. I have seen plenty of shitty driving at every level from bicycles to motorcycles, to cars, to light trucks, and up to double and triple trailer semis. EVERYONE, you included, has a duty to drive in such a way as to minimize risk to those around them. You can't stop as fast as a passenger car? Leave more room. Someone cuts in front of you, back off and recover your margin. There will be times when that means you are driving slower than surrounding traffic because people keep cutting in while you try to maintain your margin. You will still be moving forward. You, as a (supposedly) professional driver are (and should be) held to a higher standard.