How would you translate the line 我在寻人启事上看见我身份证办好 from the movie 地久天长 I'm having trouble understanding what 我在寻人启事上看见我身份证办好 means in the following dialogue. Here is some context:
A young guy gets mad at his parents and decides to go away leaving no traces (he goes missing). His parents then write a &quot;missing person notice&quot;. Long after the guy shows again and in this particular scene he's at home with his parents and a group of new friends. While the young guy is talking with his friends his mom asks him to come over for a moment and the following dialogue goes on:

Mom: Xingxing, are they from your school?
Xingxing: No.
Mom: Then who are they?
Xingxing: Friends.
Mom: Friends? They don't go to school?
Xingxing: No. Just like me.
Mom: Xingxing, do you know how long  we've been looking for you? Can't you see you're letting everyone down?
Xingxing: What do I care? 我在寻人启事上看见我身份证办好 [He walks away]

The English subtitles translate it as &quot;The missing person notice said I have an ID card now.&quot;, but what does that mean? I think the translation is not correct cause I can't make a sense of it.
This is the missing person notice:
The 2nd last sentence in the photo saying that &quot;你的身份证已经给你办理好，希望你早日回家.&quot; &quot;We have applied the ID card for you and now it is ready. Hope you come back home soon.&quot; Looks like the ID card is what the kid wants. Parents are using it to attract him. Later on, he did come home, but just to pick it up. He says &quot;我在寻人启事上看见我身份证办好.&quot; It is confusing if you see the sentence without context. This sentence missed several parts it should be:
我在寻人启事上看见我（的）身份证（已经）办好（了）