Sometimes, no matters what, where, when you cannot let some people down. 
You will always support them and you don't need to promise. 
It's like this, that's all. 

Because love, it's the same, you don't choose who, how, where, when or why.
Moreover, there is no reason. 
If someone find a reason, you can be sure it's not really love. 
Because you don't fall in love with a body, a job, a bank account, a personality or a behavior... 
You fall in love with a heart, a soul.

Someone can be as perfect as possible, if there is not THE spark, there is no love. 
A lot of people are disappointed and being wrong because "He is not what I imagined!"
Indeed, you fell in love with an Image, not with a heart, not with a soul.
So you are disappointed of what is behind his Ego, i.e., his heart, his soul.

I don't know everything about this, I don't know who is right or not, but I'm sure love works  like this. 
That's why some people can fall deeply in love with someone they "don't know". 
Sometimes, look inside the eyes, feeling the soul behind, it's enough.