1. Preparation will set you free, but it only lasts until the first cross-examination. Then everything goes to hell and you spend the rest of the trial working 24/7 to keep up with your attorney's panic.
2. If you have co-counsel, they will inevitably screw things up, leaving you to get berated by the Judge. This will happen, sure as the sun rises in the east.
3. Help! There are Zombies in my office! Zombies, I tell you! In suits!
4. You will, at some point, fall asleep at your desk. Accept this and be glad for the rest you get.
5. Expert witnesses, while very nice people, are increasingly boring in direct ratio to the specificity of their expertise.
6. There are expert witnesses in everything. Literally everything.
7. At some point during the trial, you will consider suffocating yourself in a redwell in the back of the courtroom. (For me, the first time was a couple years ago. Hour 5 of expert testimony on pus. Yes, there are expert witnesses specializing in pus. See #6 above. And #5.)