Yes, I am aware that HDFC Life has the annuity and NPS part from HDFC group and nothing to HDFC AMC. However, as I did not read much about life insurance as a sector, I did not buy anything pertaining to that sector.
In the below video, after 10 mins, the interviewer was exactly asking about why there are more outflows despite all time highs in NIFTY & Sensex
True, staying in our circle of competence and having a good sleep are very important. For example, I slashed my portfolio by 40% during March crash.
No investor can say with confidence that his particular stock will definitely beat others and at the most give a guesstimate… Investing is a game of possibilities. All I am doing is , spreading my bets across sectors and trying to allocate more to high conviction ones. For example, I added some more Laurus Labs shares after their recent Q2 FY21 results. I did not see any red flags, very good earnings outlook, all segments displayed growth but still the stock has fallen down. I hope it is for short term but I can never say that this stock cannot go down 
It is similar to applying for a job or getting a promotion, you never know how the competition fared with certainty till you see the result.
Regarding underperformance of mutual funds, I did study though. It is covered in the below post.
I think you are lucky. All my life, I have been a fan of crime fiction novels and movies, and so my natural behavior is to look for that excitement and I think in investing, you need patience. It took me sometime time to learn the lessons but overall returns have beat FDs so far.
Disclosure - I am biased about HDFC AMC and Laurus Labs as they are my top holdings