You and your best friend know each other as well as possible. The relationship between you cannot be compared to the relationship with other people - it is a completely different level of connection and love. They trust each other completely, because they know that neither one nor the other would betray the strength of your bond, so you must not hide it from your best friend.
If you are too tired to stick to your plans. We often hide from other friends and acquaintances that we have too little energy to be truly present in the interaction. You don't need to do that with your best friend. If you're too tired to go to the movies or out for a drink, she'll understand.
When you have a new crush. A new crush is something your best friend might know all about.
What do you think about her crush. True friendship is also based on frankness. If you don't like her crush, you'll tell her that too.
Where you (don't) want to eat. You and your best friend sometimes even argue about where you want to go to eat or drink. This rarely happens with other people, as you adapt quickly out of politeness.
Your biggest fears. You don't hide what you're really afraid of in front of your best friend. And the fact that you can confide in someone about your fears somehow makes you braver and stronger.
When you're homesick. Everyone sometimes feels homesick - we miss the family dog, grandma's cooking or mom's warm hug. Lucky you can complain about it to your best friend.
He knows the real reason why. Being late is something that we rarely give a real reason for in front of others. You honestly tell your best friend why she knows you.
