Image source: Getty Images.You really don't want to make mistakes when it comes to Social Security. Why? Well, because it's likely to make up a major chunk of your income in retirement. According to the Social Security Administration, the majority of elderly beneficiaries get 50% or more of their income from Social Security, while 22% of married elderly beneficiaries and 47% of unmarried ones get fully 90% or more of their income from it.