Strange person...

Last nite received a job to pickup the Russian Air Crew from the Air Force base about 60km away from Perth City. Anyway, I have not been there before so have to ask for direction from the boss. The boss sat down with me and tell me how to get there.. Fine. Bla bla bla bla.
Boss: "Ok, any question? understand?"
Me: "100% acknowledge and shouldn't be problem to get there. Don't worry, mate."
and the boss start shaking his head. As you guys know, when someone giving you instructions, then you said 100% acknowledge, instead the person say goood, but shaking the head. The first thing come to your mind is, Ooops, what's going wrong??? and you are in the mist of question marks... So do I. I asked boss "What's going wrong?"
Boss "nothing wrong, just felt you are very strange as I only tell you once and you already acknowledge. Some people just have to tell them many times before they understand."
Me :" Well, I know where am I going and What am I doing. And I'm well trained as I have to due to been working for the off-road Rally in the bush."
alright....better go home and have a rest before continue back to work at 12am later....
Cya...