Yes, really your behaviour matter in life. A person can be identified by his own behaviour towards others whether he is good or bad, humble, kind, arrogant etc. Behaviour or attitude is the key to identify things about a person. You can conclude a lot about him by his behaviour/attitude towards you and to the society.
Let us explain this with an example. Suppose you went to a coffee shop. The coffee owner interacted with you harshly, arrogantly, etc. You had a very bad experience with him. But the coffee was amazingly tasteful. No matter how good the coffee, I hope you will never visit his shop again unless there is no monopoly.
Now let us assume in a different way, you went to a coffee shop and the owner interacted nicely and humbly (to the greatest extent possible). Even if the coffee is a little bad as compared to the weird/ arrogant coffee shop owner, you will visit his coffee shop daily.
The take away from this example is that the behaviour or attitude of the two-coffee shop has an impact on your life. In a similar manner, your behaviour or attitude matter for you as well as for those who care for you as well as for other people around you. You are the only creator, destroyer of your own life. You can have a positive or negative impact on the life of others. But this totally depends on you, how you are going to do this. A large group of people want to interact with you, want to be around you if only if you behave and treat them nicely and humbly or you will see no one around you if you interact them or treat them harshly, you will be left alone in this world and you will find no one around you when especially you need someone urgently.
I deeply urge you and suggest you, to be nice and gentle with others if you want people to be around you and they should extend their hand when you need them. This will help you to create a prosperous and happier life around you. This will not only make your life easier and happier, as well as it will also make the life of people around you easier, happier and full of joy.
“Behaviour is the mirror in which everyone shows their image”
~Johann Wolfgang Von Goethe