Complex sentence: When he asked to join cadets, his mother thought it was a passing fancy and she gave it three weeks but her son found something in the structure and the discipline that appealed to what his father called Paul's "strong warrior spirit".
Split into simpler sentences: When he asked to join cadets, his mother thought it was a passing fancy. But her son found something in the structure and the discipline that appealed to what his father called Paul's "strong warrior spirit".