I'm an only child.  No siblings.  Just me, myself, and I!
Did you enjoy being an only child, or do you wish you had siblings?
Even though the term generally applies to those who've never had siblings, I actually have.
Which term are you referring to?  I am confused.  Do you have siblings or not?
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
have ideas. I never had time to dream about being anyone else. I had to work. I haven't just sat back and thought of myself or my ideas or what I wanted to do ... I've kept working. I don't have time to worry about who I admire or who I identify with. I never had it easy. I'm not at all like you ... all those people who had it easy."
In economic terms, it has been contended that the counterculture really only amounted to