Final answer:
The narrator's choice was fortunate as it inadvertently led to her sons learning significant life lessons, which was an unexpected but beneficial outcome.
Step-by-step explanation:
The narrator's decision was fortuitous because her sons learned many valuable life lessons. The key to understanding why this decision was fortuitous lies in the positive outcomes and experiences related to learning that are not initially expected. When making a decision in the hope of certain benefits, sometimes the actual rewards are different but equally, if not more, valuable. The lessons learned by her sons are the unforeseen advantages that make her decision to participate in the children's theater fortuitous.