Respuesta :

When you aren't used to something, its hard to adjust because you haven't gotten used to it. 

Example:-

If all your life, you have been sleeping at 11 PM, and you suddenly change that routine, it will be hard for you to sleep at first. 
Vampgirl108
Because your not used to it yet. For example My best friends new friend. when it first started i did not like it. but after a while i got used to her.