falling?in?love?

Why does someone who's being in love like to say it that he/she is falling in love? We can just simply say it 'in love' without using the word 'falling' in the front of that sentence, right?

For me personally falling sounds kinda hardcore. Because falling can means hurting. You fall then you hurt right the second after that. Falling can also means going down. 

So, why does everybody likes to call it falling in love? Does it mean love that comes with a bad impact? Or does it mean that love is always ends with a pain and hurtful feelings?

Or this is just me overthinking again?