Importance of current affairs-
Upsc has a hobby of asking questions based on current affairs. It has been following the same trend for many years.
Most of the topics mentioned in the UPSC mains exam syllabus are dynamic. It means the topics have to be regularly studied.
International relations, Background information on India's relation with other countries can be read from textbooks but for the recent development of bilateral and multilateral relations, one has to follow newspaper regularly for writing good answers.
UPSC questions are interesting and at the same time challenging also. Most of the times, UPSC derives current issues and asks some basic fundamental question, which is tricky to answer.