It's not really about focus it's more about desires.Its like if even on our death bed instead of desiring union of our soul with God, we desire money at our deathbed then we become a snake.Some of such stories are believable but you need to make sure it's from a trusting source.You can read about such stories from Guru Granth Sahib ji Maharaj.If someone passes away it is because his karam has been cleared for this life and his number of swaas is up.
No karam is not made based on how many people dislike you.It is based on your actions and deeds.
As to how to escape from this reincarnation, Gurbani gives a simple answer.
Raam Naam Simar Tu Jeeve Fir Na Kae Maha Kaal
Meditate in remembrance of the Lord's name,you shall live and the great death shall never consume you again.
Rehatvaan means a Gursikh who follows Guru Sahib's Rehat Maryada
Bhul Chuk Maf 😀🙏