I'm not sure if Alex got to the point where he understood the difference between gravity and atmospheric drag. I think Austin and Vinny did, but I'm not sure.
Someone please tell Drew about mission briefings at the mission select so simple objectives don't become so difficult. Just press Y at the mission select Drew!
That and that you can hit the radio button over areas of the map during missions to get more info about the mission as well.
It would also probably be useful for him to know that you can hit people with the tranq pistol in areas other than the head without setting off an alarm.
PiltdownMan's comments