Some of the most bitter people who could be very jealous and would wish you never succeed are those who have tried and failed at what you want to try.

They are angry that they failed or gave up so quickly and have told everyone that it is impossible to do it. But here you come with enthusiasm, poised to succeed at that same thing that they’ve resigned.
These bitter people pose themselves as gatekeepers that would require you to have their permission before you can cross.

This is what happened between David and his elder brother, Eliab. David’s attempt to bring down Goliath was met with stiff opposition from his brother, which could have cheered David up given his antecedents with the lion and bear and their blood relationship. But Eliab preferred to talk down on him and shout him down before other soldiers. It took the other soldiers around to get David to see Saul and then to fight Goliath.

Beware of bitter souls that have failed in the areas you wish to do well.