A Sikh is a learner.
A learner is a seeker who has the desire to know. Most people think they already know. They are not learners. They have already gathered too much information. There is no room for more.
A learner, a disciple, a shishya or a sikh has to first recognise the fact that he knows nothing.
Only then learning is possible. Only an ignorant person can learn; only an ignorant person can become a sikh, a disciple. He who is ignorant and knows that he is ignorant has the capability to learn; he is ready to learn. An ignorant person is like the empty vessel that is ready to hold water in it.
A knowledgeable person is a full vessel; whatever else is put into it will only spill over. A disciple is one who is ready to bend, who is humble and who considers knowing to be more valuable than his ego. A disciple is one who puts his head on the ground in order to get a ray of light, and who is ready to stake all to get that tiny glimpse.