Why are you going to investigate me? I'm only applying for an entry level job and I don't need a security clearance.
The interests of the national security require that all persons privileged to be employed in the departments and agencies of the government shall be reliable, trustworthy, of good conduct and character, and of complete and unswerving loyalty to the United States. This means that the appointment of each civilian employee in any department or agency of the government is subject to investigation. The scope of the investigation will vary, depending on the nature of the position and the degree of harm that an individual in that position could cause.
The requirement to be investigated applies whether or not the position requires a security clearance (in order to have access to classified national security information).