I have trouble with both sentences. In both sentences, I cannot tell what the clause "with...forever" modifies. Does it modify the verb form "has been left" or does it modify "everything". Also "left" does not make sense to me. If you could clarify your meaning, I'll try to give you a more helpful answer.

Though I am not an English speaker, I can help you with your question. As you'd probably know, the two words "attitude" and "assumption" have different meanings, and it sounds awkward if "attitude" is used in the sentence :)