Thor: Ragnarok culminates in Thor realizing that the power of lightning is within him and that he has the power to summon/call/create it. During the beginning scene of Avengers: Infinity War, why didn't he use this to fight Thanos? It seems to me that he went through all this development in the Thor movie, only to forget it at a crucial moment.
Lightning is pretty powerful, and even against a strong character, it seems like the amount that Thor can output could cause him some issues.
Is there a reason that I missed of why he wouldn't be able to use it? Even if it was ineffective, wouldn't he at least try and attempt to save his brother?