6) it could all be just hindsight. opinions aren't important. being able to make profit is.
people often buy stocks or funds with hard earned money without knowing much about the market or the funds. they act and rely on advice of friends or relatives who themselves may not know much.
i've met people nowadays who own funds but know less than i knew about funds 20 years ago. they don't know their funds' launch dates and track records, or what a prospectus is. it's hard to imagine one'd be a winner in the market without doing some basic homework.
unless the investment is a small portion of one's asset, it's best to do some basic study and then monitor it closely.
red hot bull markets are lovely. but beware of sudden deep corrections like the 1987 crash, or protracted bear markets like nasdaq that lost 75% of its value from 2000 to 2002.