No its the way you want it to be.
As EvilSOB explained, the #define just lets you write a name instead of skillX (x begin a number from 1 to 100)

You can undefine a label for a skill if you want to and redefine another label.
Example:
You have a movement.c file which labels skill1 as health
and you have a weapon.c file which labels skill1 as damage

Of course there are certain scripts around which use the skills based up on the programmers choice.