You're correct that there's more to it than just keeping something secret:

- It has to also be valuable because of the secrecy, so the number I'm thinking in my head doesn't count. But customer lists typically do have value because of secrecy.

- Trade secrecy can be destroyed if the secret gets out.

There's no reason to argue in the abstract. Here's how California law actually defines "trade secret" -- Civil Code 3426.1(d):

(d) “Trade secret” means information, including a formula, pattern, compilation, program, device, method, technique, or process, that:

(1) Derives independent economic value, actual or potential, from not being generally known to the public or to other persons who can obtain economic value from its disclosure or use; and

(2) Is the subject of efforts that are reasonable under the circumstances to maintain its secrecy.

http://leginfo.legislature.ca.gov/faces/codes_displayText.xh...