If you are an only child can you tell me if it affected your happiness in life?

I hate that my son is an only child. I fear that he might be lonely as an adult, especially around holidays. At the same time I think there are many that do not like their siblings or even talk to them. Some people have siblings but go on to live lives far away from their families so maybe it does not matter. Sometimes I think I am projecting my own insecurities about life onto my child. Maybe he will be ok in life. If you are an only child please share if your happiness in life was directly linked to being an only child.