How do you gain knowledge? Is it from watching videos, reading books or articles from internet? Is it from your family, friends, teachers, professors? Is from your own feelings? There are many ways of collecting and obtaining knowledge and as human living in the era of 4.0 nowadays, myriad knowledge sources are viral in every place, in every time. However, how do you know the knowledge, how do you come into a conclusion afrer deepening your doubt and curiosity?