Disclaimer: I do not own HHGTTG
Sometimes Arthur wonders if it's possible to bottle memories.
Since the Earth exploded, his life has become a rollercoaster ride of fear, adrenaline, fear, wonder, delight and fear. But what most distresses him is how little he can recollect of his experiences. He can never quite recall what was racing through his brain, what was racing through his body and, more often than not, what was racing past his ear with a frightening whistling sound. It really upsets Arthur that he's in the middle of an inter-galactic adventure and he can't remember most of it.
Then Ford smiles at him, and he forgets again.