What is a one-sentence summary of the following article?
If you’re in love with someone, you’ll likely long for them whenever they’re away from you. You may even miss them when they’re only away for a short time. Look for feelings of wanting to be with them every moment. This could be a sign you’re in love.  For example, you might catch yourself thinking, “I miss him,” even though he just left. Similarly, you might find yourself cuddling a pillow and imagining it’s the person you love. You may fall in love with someone who doesn't feel the same way. This can be very disappointing and hurtful, but it's best to let yourself move on. Everyone has a right to their feelings, so don't try to make them love you. Instead, get over them by sharing your feelings, grieving the loss of your fantasy, and moving on with your life. Don't wait for someone to change their mind and start loving you. Remember, a better match for you may be out there waiting for you to find them. If you continue pursuing a person who doesn't return your feelings, you're likely becoming obsessed with them. This is harmful to both you and them. Respect their choices and search for love with someone else.

Summary:
Notice if you feel a longing for someone. Pursue your love only if the feeling is mutual.