Because reinforcement learning may lack a model of the environment, it must address both the task and the problem of discovering what actions to take, making the problem more complicated and, in the speaker's view, more interesting.

“well I don't have a model at all, I just have interaction with the environment and that immediately makes the problem more, first of all it makes it more interesting,”

“but also makes it a lot more complicated.”

“Because now you no longer are trying to solve the actual problem at hand, you also solve the problem of even figuring out what to do in the first place.”