I was only a child until 2001 when my sister was born, what about you?
I have one older brother and a younger sister.  Did you like being an only child?
I definitely got more attention but it was for sure more boring. Only children were much common in earlier history.
Why were they more common in earlier history?
Whoops I meant uncommon. They are more common now because of increasing costs of raising children and women having children later in life.
Oh, yeah, I agree with that.  I have one kid and she is quite expensive!
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
this period in her life, Malvern is quoted as saying: "…until I was twenty-one, home to me was anywhere—hotels, trains, boarding houses; for my sister, Corinne Malvern, and I were ‘stage children.’ When I stopped being a ‘stage child,’ I became what they called an ingenue, and then a leading lady. But by this time I had decided I didn't like wandering about, and I began to think how nice it would be to have a