These are some 16 things every Indian should know about our country:

1. Not even once in the past 10000 years of history, India invade any country.
2. Established in 700BC, Takshila was the world's first university. More than 60 subjects were taught here for over 10,500 students from all over the world. 
3. Built in the 4th century BC the 'University of Nalanda', was one of the most outstanding achievements of ancient India in education.
4. Sanskrit, an ancient Indian language, is the mother of all European languages. Forbes magazine, July 1987 edition reported that Sanskrit was the most suitable language for computer software.
5. Ayurveda is the earliest school of medicine perceived to humans, with historical roots in the Indian subcontinent. Charaka, the father of medicine, was one of the main contributors to Ayurveda 2500 years ago. 
6. 6000 years ago, the art of Navigation originated in the river Sindh. The very word Navigation is descended from the Sanskrit word 'NAVGATIH'. This word 'NAVY" was also derived from Sanskrit word 'Nou'.
7. Though images of modern India often exhibit poverty and lack of development; India was the wealthiest country on earth until the British invasion in the early 17th century.
8. India invented the Number System; Aryabhatta invented zero.
9. The decimal system was manifested in India in 100 BC.
10. Budhayana was the first to determine the value of pi; he also explained the concept of the Pythagorean Theorem. Budhayan discovered this in the 6th century, long before the European mathematicians.
11. Algebra, calculus, and trigonometry originated from India; Sridharacharys give the quadratic equations in the 11th century. The largest numbers the Romans and Greeks used were 10^6 (which is 10 to the power of 6), whereas Indians used numbers as big as 10^53 (which is 10 to the power of 53) with specific names in 5000 BCE during the Vedic period. 
12. Bhaskaracharya was the one who calculated time taken by earth to orbit sun in the 5th century itself; the time taken by earth to orbit the sun was 365.258756484 days.
13. When all over the world there were only nomadic forest dwellers, Indians established the Harappan civilization in the Sindhu Valley (Indus Valley) 5000 years ago.
14. Shatranj/ AshtaPada, the modern say Chess was invented in India.
15. Until 1896, India was the only root of diamonds in the world- reported by the Gemological Institute of America.
16. 2600 years ago, Sushruta and his health scientist were the first to conduct complicated surgeries like cataracts, cesareans, fractures, artificial limbs, urinary stones, brain surgery, and plastic surgery; with over 125 surgical equipment. Sushruta is acknowledged as the father of surgery. 

Note: India is a country with several cultures and vast history, these are only some of the important facts about India which every Indian must know.