i always wondered how it would be like to be an only child, someone with no siblings
You must have brothers, sisters, or both! Which means you are VERY lucky! What appeals to you? 
all throughout history only children are actually not common i have one brother
Is your brother older or younger? I have two younger sisters, so I rarely had to share stuff or worry about competing with them. But I did take care for them!
to the country.
From 1979 to 2015, the one-child policy in the People's Republic of China restricted most parents to having only one child, although it was subject to local relaxations and individual circumstances (for instance when twins were conceived).
Families may have an only child for a variety of reasons, including: personal preference, family planning, financial and emotional or physical health issues, desire to travel, stress in the family, educational advantages, late marriage, stability, focus, time constraints
as all those events that may appear to be coincidental but which are actually probable.
An example would be to consider a friend you have not seen for years when you are on holiday (an unlikely event). Before saying it is fate or coincidence, think what is in the petwhac (meeting any friend from around the same period, or friends of your brothers, sisters or parents, old flames, neighbours, teachers, someone who worked in the local chip-shop... the list is probably endless, and