Thanks all and JUL3 (you were right, my controls went awry), I am now able to aim.. Man I feel like a noob, I did all this years ago. Now when I aim at the thing across the room and hit, the lift doesn't go down. I am being punished.
Right mouse button - left doesn't seem to do anything with the gravity gun.. I checked control setup and left mouse doesn't seem to list anything, doesn't seem normal.
I'm going nuts. I have spent about 2 hours on the elevator trying to shoot that thing across the building that makes the lift go down but when I suck an orb using the gravity gun and fire it, it goes in a random direction and never into the thing I am supposed to hit. What am I doing wrong...