Whether it's their birthday or a promotion, if they have invited you to celebrate their happiness and precious experiences, then it definitely means a lot to them.
At that point if you are someone who is not giving it that much importance, then you are making them highly disappointed and unhappy.
4. You are constantly ignoring them.
Do you remember that time when the love of your life ignored you?
Can you recall how it made you feel? Well, I am sure that it was the worst feeling in the world and you don't even want to talk about it. Similarly, when you ignore the people who matter to you, it fills their heart with despair.