The quote describes a woman who has a profound effect on a man's emotions and mental state, making him feel childlike and overwhelmed. Her presence is so captivating that it leaves him feeling disoriented, as if he is not equipped to interact with her on an adult level. This highlights the power some individuals have to intimidate or enchant others.
The author, P.G. Wodehouse, uses this imagery to convey the nuances of attraction and the impact of charisma. The protagonist feels both unprepared and awestruck in her company, illustrating how certain interactions can evoke vulnerability and nostalgia for simpler times in life.