Concept:
Teaching is considered a noble profession because it contributes to the intellectual, moral and social development of individuals and society.
Step 1: Understand professional satisfaction.
A teacher enjoys the profession when he or she is motivated by the purpose of educating and shaping students' lives, rather than by authority or personal recognition.
Step 2: Analyse the options.
• Controlling students -- Not the aim of teaching.
• Receiving respect from students -- A result, not the reason for enjoying teaching.
• Being more qualified than colleagues -- Irrelevant.
• Realising teaching is a noble profession -- Correct. \checkmark
Step 3: Final conclusion.
Hence, a person enjoys teaching as a profession when
\[
\boxed{\text{he realises teaching is a noble profession}.}
\]