The 46-year-old victim was walking along Bagshot Road close to the leisure centre when the man ran up to her, started hitting her, then stopped and began apologising and trying to excuse himself.
He followed her along the road towards the Hilton Hotel, continuing to apologise, before walking off towards Birch Hill.
The victim called police after the incident at 11.20pm on Friday  last week. She suffered a bruised cheek and a bloodshot eye but did not need hospital treatment.
Her attacker is white, under 18, slim, with short, dark hair and an earring in his left ear. He wore a diamond-patterned whte and black sweater jacket, possibly a zip-up.
Anyone with information should contact PC Lou Grinney at Bracknell police station via the 24-hour Police Enquiry Centre on 101 or the charity Crimestoppers anonymously via 0800 555 111 or www.crimestoppers-uk.org