If you are not accustomed to thanking people (so if somebody holds a door open for you, you don’t say thank you), you can forget about being an eved (servant of) Hashem.

The most important thing you need to learn in This World is how to feel thankful and how to express your thanks. It is only then that you will be on the first rung of the ladder to personal growth. ~ R’ Avigdor Miller zt”l