Hello! Are you or do you know someone who is an only child? As in no brothers or sisters at all?
Hi, no I don't know someone
Its interesting because Its always been something that is very uncommon through out history. 
Ha ok, interesting
China actually had a one child policy from 1979 to 2015, that restricted parents to having one child! Isn't that crazy?
Yes, heard about that. I am happy that this policy has ended.
Right? There were cases that were evaluated on an individual basis, exceptions were not made often
I am sad to hear that
Only child
An only child is a person with no siblings, either biological or adopted. 
Children who have half-siblings or step-siblings, either living at the same house or a different house - especially those who were born considerably later - may have a similar family environment to only children, as may children who have much younger siblings from both of the same parents (generally ten or more years).
Overview.
Throughout history, only children were relatively uncommon. From around the middle of the
into personally obviously is very different. They are having completely subjective experiences, but that doesn't mean [they're] not incredibly receptive to one another and it clearly creates something in-between them. And that's what love and sex and intimacy and all that is. Someone who is listening to you, hearing you, there for you, that's the person you end up having a relationship with, sexual or just emotional or whatever. I don't know if that has to do with gender necessarily".