How do I know?

One of my first poems that I've been proud of. Written around Valentine's Day of 2009.

How do I know when I love you?
Between friends and lovers, where is the line?
If I were to kiss you, and you kissed me back,
Would that be the signal that your love is mine?
Is it when you’re on my mind always,
But still I want to think of you more?
Is it when I would gladly walk a hundred miles
To finally collapse when I knock on your door?
Or when I’m free to be myself around you
And I don’t have to hide behind a mask?
Maybe I’ll know when I love you
When these questions I won’t have to ask.