From my own personal experience, these are good signs (aside from the minor fact that a doctor wrenched an eight pound baby from the incision in your gut) that you are a parent:
After a partner recites a string of swear words you remark that he has a "poopy mouth!"
You think your job is tough but you realize that if you went home you'd have to face diapers filled with black bean and strawberry end-product.
You wish that you could make formal discovery requests on your kid requesting the production of the remote control battery cover, your trusty pen drive, and all the refrigerator magnets he has been hiding the past week.
When your coworkers mention "happy hour," you immediately associate the term with a quiet room, a king sized bed, and an uninterrupted snooze.
Out of habit, you get the urge to clap encouragingly each time someone pleases you.
You think the office environment would improve greatly if everyone would just have some goldfish crackers and take a nap.
An associate starts whinning and your first instinct is to locate his binky and plug it in his mouth.