Is there a value for a single moment of mindfulness (without others) ?

what is the value of a single moment of mindfulness- and is it worth anything if not combined with other moments when i do a good action to help others even a small one it has its benefit to the other without even looking at its affect on the practice even even if i do one deed like washing the dishes of the family than i dont do nothing for 4 months its worth something if i meditate for 30 minutes or be mindful while doing some action for 30 minutes and than i dont do meditation or even be mindful for 4 months - is it worth something ? why you say so ? (there are so many teachers talking about the importance of consistent practice which makes me think that its not worth anything) This is a continuation of a precius question i ask which is very similar but not exactly the same : https://buddhism.stackexchange.com/questions/18589/is-there-a-point-for-a-not-continues-practice