We've probably all heard at least one person in our lives say that their boyfriend or girlfriend completes them. This implies that something was missing, or wrong, prior to the relationship. The experts I spoke with agreed that if you're looking for someone else to complete you, it's time to take a break and figure out why it is you're feeling incomplete in the first place. 

"If you're feeling empty and lost, you might think that by being with someone, you'll become a whole new person because they complete you," Reddle said. "That's not how dating should work. You want to find someone who will complement your personality, not give you a personality and complete you." 

Casamento agreed, telling me that if you feel like you can't exist without someone else, it's because you don't enjoy spending time with yourself. "Real joy comes from inside yourself — not from another person. So, if you want to be with someone just because you don't want to be alone, you really need to be alone, face whatever issues you're avoiding, and do some work on yourself."