Secret clearance. What's all involved with obtaining one?

Is forgetting you had friends a security risk?

Forgetting about some of the good friends I hadn’t spoken to in 20 years is not a security risk; forgetting where I left the test tube of Muscovium emitting 1.21 Gigawatts of gamma and neutron radiation is a security risk though.

It’s green, glowing, and hot. Let me know if you see it laying around anywhere.