Another HGV driver here, this guys behaviour isn't endemic of all of us.....honest! Unfortunately it's the case that there are complete mazda's about in all vehicles be that hgv's, cars or bikes. I was sat at traffic lights on a roundabout just yesterday and in the next lane was a biker followed by a lorry right up his arse. He kept revving his engine making the truck lurch forward (right behind the bike) so the biker motioned to him to stop and keep back, which the hgv ignored. To his eternal credit (from what i could see) when the lights went green the biker just sat there and didn't move much to the other drivers annoyance. Looked like the bike tore off before the lights went red leaving the lorry stuck there! I can't really add any advice that hasn't already been said but just ride for yourself and don't let yourself get panicked by it, as i dare say that's a sure fire way of making a mistake and ending up under their wheels coz they're following so close. Dominate your lane, don't give anyone the excuse to have a go and if it's bothering you that much pull over when safe to do so and let them pass. It's really not worth the distraction to your attention to what's going on ahead. Good luck.