has changed or has been changed.

[littlepun]

Hello, i have a question about present perfect tense.
It would be great if you could help me figure that out. today i was listening "Everything has changed" and I noticed that when I talk about something that is already started and affected to now or ( a period around now ). We always use present perfect, but what i do not understand is this part. I will write these sentences to compare.

S+have/has+v.3+Object
I have changed my car.
I changed my car and now i am using a new car. the old car does not belong to me anymore.

S +have/has+v.3
Everything has changed
In this case i don't get it clearly. Actually I've heard this so many times, and I understand it. For example, when i talked to my friend about the computer game. The path was updated and there was everything new. and my friend said "Everything has changed".

I'm confused when I compare it to another sentence like I have changed my mind.
I have changed my phone number.
I have changed my wallet.
but for everything has changed I think it could not be changed itself.

Why don't we say "Everything has been changed instead because it does not have an object ?
Sorry for making this confusing and thank you for your help to make me understand this.
have a good day.

[Alan]

The verb 'change' can be both transitive (as in 'I have changed my car') and intransitive (as in 'everything has changed').

Any dictionary will provide this kind of information for you!