No, you didn't read this wrong, it is possible to create a signature line for yourself in SureClose.  You just have to be clever about it.  First, are you using the Corporate Message feature?  If you aren't, check out this Helpful Hint post.  If you are a site admin, you can create a new Corporate Message through your Admin tab.  If you aren't a site admin, you should be able to have your admin do this for you. 

By using the merge fields for your name, your company, your phone number, and anything else you want to include in your signature from your contact entry, you can create an email signature as a corporate message.  Once you have created your signature line as a corporate message, you can choose the "pre-written message" option when sending emails and grab your saved signature from the pick list. 

One final tip: The subject line from your pre-written message will override any subject heading you type manually into your email.  So, be sure to drop your signature in from the pre-written message field FIRST and then type your subject line and email message.

If you have any questions about SureClose, please contact me.  I hope this helps!