I previously applied for a re-entry permit a year or so ago but never left the country (Decided to go to a different college). They did confirm mailing it to me but I never actually got the document. At the same time, I didn't track it down because I had already decided I wouldn't need it.

Flash forward, I'm abroad on a 3 month trip and hope to return home in a few weeks. Would this non-use of a re-entry permit come to bite me in the ...? I never actually left the country previously. Should I make an effort to cancel it?

I'm an American PR and I've been in the US for the past 20 years.