Complex sentence: When he was performing this stand-up comedy in the 1930s, he fluffed a joke so that it came out as nonsense: this got a good laugh so he made such double-talk the focus of his act and became especially known for this.
Split into simpler sentences: When he was performing this stand-up comedy in the 1930s, he fluffed a joke so that it came out as nonsense. This got a good laugh so he made such double-talk the focus of his act and became especially known for this.