The use of "but" is the normal contrastive one. I think the sentence is intended to be understood like this: This is one reason why [you might go to bed feeling motivated to make a change in your life, but when you wake up you find yourself falling back into old patterns].
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
The use of "but" is the normal contrastive one. I think the sentence is intended to be understood like this:
This is one reason why [you might go to bed feeling motivated to make a change in your life, but when you wake up you find yourself falling back into old patterns].