We store memory in our touch, sight, smell, hearing and taste. If anyone has a sixth sense, what best describes that but the connection to the memory of others? The memory of a great day can be stored in your fingertips, in a scent, so that a touch or particular smell will remind you of it immediately.
In a way, everything we do in our daily lives - good or bad - soaks into us, building a memory bank that is constantly referred to by our subconsciousness. What we fill our senses with affects us not only on a basic, visable level, but it also affects our very inner experience with which we see and shape our world.
So, taking extra care at what we constantly feed our senses with - controlling what we say, do or even eat for example - will help the upkeep of a robust and healthy memory. It will also become a collection of scenes that we'll constantly want to rewind and play back in our minds sometime.
If our life isn't something we want to look back on, then aren't we doing something wrong?
Moreover, next time we treat someone badly we should remember this: we are hurting ourselves, too. That bad action will be stored in us, logged away, ready to pop up at the slightest prompt from our senses. It will come back to haunt us. It may even disable us.
We can reverse all that by giving ourselves some good rules to live by and (not or) doing someone a good turn when the opportunity arises.
This will also help nurture respect in us and those around us, including the planet itself.
Possibly it seems ungenerous that we should help others because it benefits us, but even if you start doing good for selfish reasons, pretty soon it'll make sense to do good just for its own sake.