PhD and past performance: Any correlation?

Recently, I received an e-mail from one of my friends. He is working in a corporate sector and planning of doing PhD. From his writing, I can feel that he is 150% sure on his chosen topic as he claimed to have more than 10years working experience in that particular area. He is also confident that he is qualified to enter any G8 (top uni ) in Australia based on his past academic performance. He is confident that he could complete his PhD on time (3 years) or may be less.

My replied to him: Good, you have meet the criteria needed to enroll as a PhD student and you have more than 100% confidence to start your journey but my advise is that don't be over confident! Based on my two years experience (in my horrible third year now..heee) , my personal opinion is that PhD does not really correlate with your past experience and academic performance. Ini hanya based on my observation and tak empirically tested lagi nooo...heeeee...

I have seen few people yang ada tip-top academic performance in their entire life (best student masa SPM, among the top students masa bachelor and master degree) need to go back after 1 year starting their journey. Ada juga yang kononnya expert in the area of study and have years and years working experience in that particular area but still struggling in their journey.

Ada juga, yang just have "so and so" past academic performance and have no working experience what so ever in their area of study tapi dapat complete on time. So, my conclusion: PhD does not correlate with any of these two factors.

PhD is not 100% about the topic that you are researching but more on how good/clever/smart you are in handling challenges in your life through out your PhD journey. To me, perseverence is more needed compared to confidence in your PhD journey.

Another thing, to those yang plan to do PhD, buang jauh jauh your ego , especially yang dah jadi bos-bos kat Msia. Doing Phd meaning you are going out of your "comfort zone". Sometimes you need to do things that you don't really feel like doing. You must always remember, once you dah ada tag student, kat sini, you need to live as a student ( ini untuk golongan biasa biasa le). No more luxury. Here, nobody care about your pangkat or status kat Msia. I am telling this because there are people yang susah nak adjust. Kena ingat pesan org tua tua "masuk kandang kambing mengembek, masuk kandang kerbau menguak". Kalau guna approach " cerdik tak boleh tumpang, bodoh tak bole nak ajar", you will end up jadi "kera sumbang"....heeeee