Some throw up, some don't feel a thing (aka Bill Clinton), some get goofy, some get quiet. No way to really tell how it will affect you. As stated above, don't smoke the whole thing in one sitting...it won't wash off in the shower and you'll have to just wait it out until it finishes doing what its gonna do.
Talked to a Dr. who'd tried it for the first time, just curious. He'd had enough to drink to get his courage up to ask someone to let him try it. He absolutely hated it because he wasn't in control of the feeling. He woke up in the sink in the kitchen where he'd passed out after throwing up. Said he couldn't understand how people liked that feeling, but wasn't aware of the tolerance factor after partaking for a while and your body gets used to it. His interest was more why people (professional linemen, etc where bodies take abuse) use it for pain management, than just the buzz associated.

experience is a freakin' awesome teacher....