"One good turn deserves another" this is one quote I cherish and love because of its meaning.
The world is full of hate and selfishness, everyone is about their own self and not concerned about what happens to the other person.
Also ingratitude is another cancer that has eaten deep into the fabric of humanity, many people do not regard what you have done or see what you do for them as a big deal, they feel entitled and as such do not see a need to appreciate.
If we inculcate this quote "one good turn deserves another" into our day to day life, it will help curb the selfishness in the society because every good deed done will attract a good deed in return. Everyone will have a feel of goodness, knowing fully well that if I do good to Mr A, assuredly, I will get a good deed in return. Though this should not foster an entitlement mentality but it should create a sense of doing good and spreading love.
Also, the issue of ingratitude will be tackled as people tend to appreciate the good deeds done to them by extending a hand of help when the need arises. When you appreciate people for what they do, you always look forward to reciprocating their kind gestures and the world becomes a better place for everyone.
Hence my favorite quote is "one good turn deserves another"