I'd killed several deer with a rifle (all does, as I'd not yet killed my first buck, even with a gun, when I started bow hunting), and just shooting a doe with a rifle at 150yds would have me shaking like a leaf. I could only imagine how I'd react if I was 20ft up a tree and the deer was only 20-30yds away, so I figured I'd give it a try.
My 2nd season of bowhunting was the first time I ever let an arrow fly at a deer, I was shaking so hard I just knew I was going to fall our of the tree (I did have a harness on at least). She was perfectly broadside, about 8 yds from the base of the ladder stand I was in.
I fired. I missed (shot under her). She ran off.
I sat there in the stand for the next half hour shaking so hard I thought I was going to piss myself. I knew if MISSING a deer could give me that much of an adrenaline rush, I was hooked forever.
I've gotten 1 shot since, a little 1-horn spike quartering away at 25ish yds. Put the arrow in right behind his rib cage and exited through his far-side front shoulder. He ran maybe 40-50yds if I recall, and piled up. So right now I'm batting .500 with my bow.
To date, the only thing that has given me that much of a rush was having a big turkey start gobbling on the ground right behind me when I didn't even know he was there.