Final answer:
Jenna is prompted to try something new by a significant childhood memory, which horrifies Claire due to the potential for deviation from the norm or the risks associated with acting on potentially unreliable recollections.
Step-by-step explanation:
In the context provided, an important childhood memory that triggers Jenna to try something new is not explicitly described. However, discussions about memories affecting current decisions suggest that a profound memory or a series of memories from Jenna's past have inspired her to step out of her comfort zone, attempting something beyond her normal behavior. The reaction from Claire indicates that whatever Jenna is considering is alarming or distressing to her, hinting that it might be unconventional or risky.
Claire's horror could stem from a fear of deviation from the norm, especially given the intense and somewhat macabre undertone of some of the references, Claire might be particularly sensitive to actions that evoke the past or suggest psychological distress. Indeed, caution surrounding the authenticity of memories, like those questioned by Loftus in relation to induced misinformation or false memories, could be why Claire is horrified at the prospect of Jenna acting on potentially unreliable or misunderstood recollections.