If you are complaining, the law of attraction will powerfully bring into your life more situations for you to complain about. If you are listening to someone else complain and focusing on that, sympathizing with them, agreeing with them, in that moment, you are attracting more complaining situations to yourself!
Feeling gratitude for money you pay out guarantees you will receive more. Gratitude is like a magnetic thread attached to your money, so when you pay money out, the money returns to you, sometimes equally, sometimes tenfold, or a hundredfold. The abundance you receive back depends not on how much money you give, but on how much gratitude you give. You could have so much gratitude when you pay a bill for twenty dollars that you could receive back hundreds of dollars.