Terry McMillan writes about midlife with the confidence of someone who knows that reinvention is rarely tidy and almost never quiet.

I Almost Forgot About You follows Georgia Young, a successful optometrist in her fifties whose apparently settled life has begun to feel strangely airless. The death of a former lover prompts her to revisit the men and choices that shaped her past, while reconsidering work, friendship, family and the possibility that she has mistaken stability for fulfilment. The premise could easily have produced a sermon in sensible shoes. McMillan wisely gives it a pulse.

Her prose is vivacious, accessible and deeply conversational. One contemporary assessment described it as accessible, heartfelt prose, while another praised its rich, colourful dialogue and energetic handling of character. Those observations get at McMillan's central strength. She writes people through their speech. Conversations carry personality, history and social tension, often with the ease of gossip between people who have known each other long enough to stop pretending to be polite.

That ease, however, is also where the novel begins to sag. McMillan sometimes lets dialogue become a substitute for dramatic construction. Characters explain feelings that a more controlled novelist would allow to emerge through gesture, silence or action. Some conversations arrive already carrying their own interpretation, as though the novel has grown nervous about leaving anything for the reader to infer. The prose is fluent, but fluency is not the same thing as precision.

There is also a looseness to the structure. Georgia's various relationships and personal complications do not always transition gracefully, and some narrative threads seem to wander away rather than conclude. The effect is oddly appropriate to a woman trying to work out what she wants from the rest of her life, but literary appropriateness does not excuse every structural indulgence.

Still, McMillan's ear for social detail is excellent. Her characters possess the irritating intimacy of real friends and relatives. They interrupt, tease, judge, forgive and occasionally say precisely the thing they should have had the sense to keep to themselves.

And here I will be uncharacteristically generous: when McMillan gets the balance right, the novel is genuinely warm. Its humour gives its reflections on ageing and regret a human scale, preventing the whole enterprise from collapsing into inspirational pamphlet territory.

The writing is occasionally sprawling and over-explanatory, but it has something harder to manufacture than elegance: life in its voice.

Verdict: a generous, lively novel whose conversational brilliance is sometimes undermined by an inability to let a conversation end.