If you're the sort of person who enjoyed The Time Traveller's Wife, I bet you loved time travel books as a child.
It's a special genre, really - in which children are introduced to problems of philosophy and physics, and led to wonder for the first time if the past still exists, and even if we might be ghosts ourselves.
When I was growing up, time travel adventures were my favourite sort of story.
Here are three of the classics, all ideal for children of around nine or older - and very enjoyable for grown-ups, too.
The Amazing Mr Blunden by Antonia Barber (whose real name, weirdly, was Barbara Anthony). Published in 1969, this is a rather intriguing ghostly tale - gripping, dramatic and well thought-through. Lucy and James are whisked away from poverty-stricken 1950s London to a country mansion where they encounter another brother and sister from 100 years before and discover how to experiment with the 'wheel of time'.
Tom's Midnight Garden by Philippa Pearce. This 1950s tale concerns a boy who discovers a clock that strikes 13 and a Victorian garden. The pace is more reflective than Mr Blunden, but builds to a beautiful climax with ghosts skating through the frozen fens and a mysterious old lady.
Charlotte Sometimes by Penelope Farmer. I think this is my favourite of this trio - and the title is up there with the best book titles of all time. The novel explores the question of identity, posing the question 'What would happen if people did not recognise you? Would you know who you were yourself?'
Also published in 1969, this is a mystery about Charlotte, a new girl at boarding school who slips backwards and forwards between her own time and 1918. In doing so, she swaps inner lives with a 1918 schoolgirl called Clare - thus, she is only Charlotte sometimes. The tone is dream-like; the ending bittersweet.