'Forgetful' in the Bible

Be not forgetful of hospitality; for by it some have unawares entertained angels.

But of doing good and communicating of your substance be not forgetful, for with such sacrifices God is well pleased.

But he that fixes his view on the perfect law, that of liberty, and abides in it, being not a forgetful hearer but a doer of the work, he shall be blessed in his doing.