Os detalhes variaram de história para história e foram geralmente encobertos completamente.
Este é o Lampshaded na novela Cold Fusion , que lista uma variedade de razões (principalmente technobabble e terceiros intencionais interferência partidária), de uma variedade de histórias antes de admitir que às vezes as lembranças são retidas:
‘Well, if he’s your future self, why don’t you remember all this from first time round?’
‘Does everything have to have a reason?’ Forrester asked.
‘Perhaps it’s magic.’
‘No, no,’ the fifth Doctor said, ‘the rules of time travel are very precise, and Mr Cwej here has a good point. Now, on both occasions that we met Omega, that was straightforward Blinovitch Conservation.’
‘That was true all three times, yes, but it doesn’t apply here,’ the other Doctor noted from underneath the console.
‘Yes, yes, I know that. Now, Zodin erased our brains with mind rubbers.’
‘I remember it well.’
‘But that hasn’t happened this time. The crashed TARDIS might have had misphased Relativity Displacers.’
‘It might,’ the seventh Doctor conceded, ‘but it didn’t.
‘Tachyon Backflush?’ the fifth Doctor suggested.
Chris sniggered. ‘Sorry – it’s just that it sounds rude.’
Forrester shook her head disbelievingly. Her Doctor stood, brushing himself off and taking his umbrella back from his past self
The fifth Doctor straightened. ‘There is another possibility.’
‘Go on.’
‘You do remember. You’ve remembered all along.’
The Doctor smiled enigmatically and tapped the side of his nose.
At the pre-arranged signal, Forrester knocked out the fifth Doctor with a swift blow to the back of the head.