famous example is the game Montezuma's Revenge where the goal of the agent is to navigate a bunch of ladders jump over a skull grab a key and then actually navigate to the door - in order to get to the next level and the problem here is that by taking random actions your agent is never gonna see a single reward because you know the sequence of actions that it needs to take to get that reward is just too complicated it's never gonna get there with random actions and so your policy gradient is never gonna see a single positive reward so it has no