Memory Memories were the mental record of a lifeform ' s past experiences . Two of the Doctor ' s companions had eidetic memory : Zoe Heriot ( TV : " The Wheel in Space " ) and Melanie Bush . ( TV : " Terror of the Vervoids " ) Jamie McCrimmon and Zoe Heriot ' s memories of their time with the Second Doctor where erased by the Time Lord s before they were returned to their original times . ( TV : " The War Games " ) As his other selves fell victim to a time scoop , the Fifth Doctor felt himself being " whittled away " and commented on the importance of memory . ( TV : " The Five Doctors " ) According to Madame Xing , by the time the Eighth Doctor visited her , his memory had been interfered with on thirty - seven separate occasions , with eight of them still uncorrected . ( PROSE : " Halflife " ) The Tenth Doctor had to erase Donna Noble ' s memories of their travels together , to save her mind from being overwhelmed by the Time Lord knowledge she gained from the meta - crisis . ( TV : " Journey ' s End " ) A memory worm could suppress recent memories , causing short - term amnesia . ( TV : " The Snowmen " , " Time Heist " ) Clara Oswald read the Doctor ' s name in " The History of the Time War " . When that timeline was later averted , however , she had no memory of it . ( TV : " Journey to the Centre of the TARDIS " ) The telepathic circuits of a dead TARDIS retrieved some of those lost memories . ( TV : " The Name of the Doctor " ) Retcon was a drug used by Torchwood to remove memories of the organisation and / or alien encounters from witnesses . ( TV : " Everything Changes " , " Adam " , " They Keep Killing Suzie " , " Meat " , " Something Borrowed " , COMIC : " Shrouded " ) The drug was also used by other individuals and organisations , notably the mayor of the trap street , Ashildr . ( TV : " Face the Raven " ) River Song used Mnemosine recall - wipe vapour to delete the memory of her encounters with the first nine incarnations of the Doctor . ( GAME : " The Eternity Clock " ) The Black Archive of the UNIT was provided with a memory filter as a security system . ( TV : " The Day of the Doctor " ) Because their time streams were out of sync , the War Doctor and the Tenth Doctor couldn ' t retain memories of saving Gallifrey along with the Eleventh Doctor . ( TV : " The Day of the Doctor " ) In order to prevent Clara Oswald from dying , the Twelfth Doctor tried to use a neural block to erase himself from her memories . Upon learning of his plan , Clara reversed the polarity of the device and the Doctor lost his memories of her instead . ( TV : " Hell Bent " ) The Doctor ' s memories were restored near the end of his life when a glass avatar of Bill Potts allowed him to see her once more . ( TV : " Twice Upon a Time " ) After Bill Potts ' s encounter with a puddle of sentient oil in the form of her friend Heather , the Twelfth Doctor intended to wipe her memories of the event . Bill realised his intentions and pleaded him not to . Eventually she gave in but before he could go through with it , she told him to imagine how it would feel if someone did it to him . The Doctor , perhaps remembering how Clara Oswald distorted his own memories , reconsidered his actions and allowed Bill to remember . ( TV : " The Pilot " )