This seems to be a dumb question on the surface and it is also a question that many people have tried to answer through various means, such as emotionally(this is considered a spirituality of sorts or metaphysical aspect) or mentally(philosophical thinking, reasoning and logic). As far as I've come to discern, any emotion is an instinctive and/or reactionary effect which happens due to some other cause. This cannot be denied.
If you love, you do so because of a cause creates the connection/relation you have with whatever it is that you love. However, before you can actually love anything, then you would have to love yourself. You cannot take any action for another person out of love without actually loving yourself first. It is impossible. And, you cannot love yourself, unless you are first able to recognize that you love yourself. You have to have a reason to love yourself. You must reach a point where you have come to accept yourself completely and honestly before you can love yourself. That requires you to be completely honest with yourself and to do that, you must remove your ego from the equation.
Love is not about YOU, but is about how well you know and understand yourself and your life. Yes, that might sound like a contradiction, but I will explain. Every person has a battle with themselves, and it's that battle you must win in order to bring about love for yourself. What battle? The battle I speak of is Ego vs Conscience. There are some aspects about living that are derived from Ego, but when it comes to honest actions then you would be no longer talking about Ego, but would be talking about Conscience. You need to recognize the difference to be honest with yourself and if you're unable to do so, then you are in fact dishonest. Thus, loving yourself is impossible.