I know there is a thread concerning this but, I was a little confused when a fella said that it could be installed on two computers but not at the same time.  Would I have to uninstall it on pc to use it on my laptop or can both carry current simultaneous installation?

Yes, you can install SONAR on both machines and leave it installed on them. You are just not allowed to use SONAR on both machines at the same time.

I wonder what would happen if you did use them at the same time? Do you think gremlins would come out of your pc and handcuff you to your chair or something.

yes, you can install Sonar on multiple computers you own, but you shouldn't run it concurrently on separate computers. If you are a studio that needs to run Multiple instances concurrently, you should license those separately. Or differently, if you and your kid both want to use Sonar at the same time every night (and not together), you should license both copies.
 
+1 for Scook's answer.