I used to date a woman whose hippy mother decided that last names were slavery, she's the person who turned me onto this list. The experience really opened my eyes into the anglo/usa-centric nature of most app development best practices, and how complicated it must be to work as a localization engineer.

She suffered quite a bit, any call to a government agency, especially FASFA student loans (btw fuck you FASFA, fuck you), would often end up in tears after hours of pleading to them she was a real person, or explaining "just freaking search me this way, it's how they did it the last time I spent 2 hours on the phone with you). The only benefit is that having only one name makes it rather difficult to google/facebook stalk you.

tl;dr: Not everybody has a name like yours. Don't use "first name", "last name" for somebody's name. Just give it a 512-byte or larger UTF8 field, and move on.