Not the long hours you spent at work, brainstorming something that might save the (clients from saving the) world. Also not the cruel comments, heart-wrecking deadlines, or passive aggressive manners the bosses will throw near the award season.
It's the mind-fuck atmosphere. The world of creative ideas and snob geniuses who rule it. The space that open enough to change any heart, the wind that blows just enough not to give any sane-mind a break.
You'll get really used to it. You'll learn the pace, the speed, the crack, the loose ends. Making excuses to abuse your own self with a judgement of how revolutionary your thoughts were, are and will be. And finally make a self-proclaimed peace that it's okay to feel that you're better than anybody. In the industry. In the country. In the world? Probably in the world you create on your own. Yeah. Because, you know better.
Once you got in, you'll never had the guts to get out. Because what else you know to do better than this? You don't know.