I’m sincere in drink, remember? (9)

I believe the answer is:

reminisce

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'remember?' is the definition.
(reminiscing is a kind of remembering)

'i'm sincere in drink' is the wordplay.
'i'm sincere' can be anagrammed to 'REMINISCE'.
Though, I am not clear how this is indicated.

Can you help me to learn more?

(Other definitions for reminisce that I've seen before include "Recollect past events" , "Indulge in recollection" , "Look back at events" , "Cast mind back over old times" , "talk about the old days" .)

I've seen this clue in The Independent.

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