Can everyone feel/have romantic love connections and are their biochemical reasons why some cannot seem to have them ?

I wonder about this a lot. I'm aware that romantic love connections are a combination of a lot of things working together to bring about a particular outcome, but is it possible that some people just cannot have them?

I'm no expert in human psychology or biology but I reckon there is no one single answer laying the reason squarely at one's social conditioning/upbringing or psychological state of being, or at one's specific biological/biochemical situation (ie. pre-programmed or perhaps 'learnt/conditioned' responses that trigger certain hormones, etc. to be released at particular times).

Also i wonder how understanding (or not) one's own sexuality, etc. plays a part?