'Forgetful' in the Bible

of the hospitality be not forgetful, for through this unawares certain did entertain messengers;

and of doing good, and of fellowship, be not forgetful, for with such sacrifices God is well-pleased.

and he who did look into the perfect law -- that of liberty, and did continue there, this one -- not a forgetful hearer becoming, but a doer of work -- this one shall be happy in his doing.

for he with whom these things are not present is blind, dim-sighted, having become forgetful of the cleansing of his old sins;