Without getting into details:
"Kirat Karo Wand Chako Naam Japo". This defines a Sikh to Me.
Building on what B4ND4 veer said, a Sikh is a student:
A child asked his mom once "Why has God send us on this earth, and when our time is done, we have no choice; we have to die and go back to God. Why send us in the first place when we eventually have to die and go back? What a logistical nightmare!!!"
Mom: "To Learn, to gain knowledge"
Child: "What?"
Mom clarifies: "In the mornings, even if you don't want to go, I force you to go to school. I pretty much drag you to school. Because, I want you to learn something. However, I the one who forced you to go, eagerly wait for you when school is done, and I am worried if you are late. In the same fashion, God forces you to leave and become a life long learner (SIKH), but when your time is done, he eagerly awaits you"