have a short memory

have a short memory (third-person singular simple present has a short memory, present participle having a short memory, simple past and past participle had a short memory)

1. To forget things quickly, especially negative things that should have an impact on one's decision.

• Not to be confused with short-term memory.

• mind like a sieve

• “have a short memory”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.
• “have a short memory” in Longman Dictionary of Contemporary English, Longman.
• “short memory”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.