Lessons to be learnt from 3 MISTAKES of Warren Buffett :
1) Be extra careful when investing in a company that appears to be similar to a previously successful investment.
(Dexter shoes - lost $3.5B as reported in 2007 letter to shareholders - success in other shoe companies led to the bias)
2) Once you realise a mistake, act fast and accept it (i.e.sell). Do not wait in hopes to be able to justify your purchase one day.
(Tesco - big mistake with investment by dawdling)
3) Don't miss an opportunity sitting back and just admiring.
(Amazon)