Until a few days ago, I completely forgot that I had to update my address changes with USCIS each time I move after getting a green card. I was scared of consequences and searched the internet on others experiences. Upon searching the web, I came across a lot many cases where people had forgotten to update address. I found people had updated their addresses 1, 2 , 3 even 4 years after moving and there was no problem with their travel or citizenship etc. In all the cases, there they had moved only once.
My problem is that I am into consulting and over 2.5 years, I moved from address A to B to C to D. My address with USCIS is address A, where green card was sent. While filling the update form A-11, it asks for current address (D) and "LAST address". My question is that in this column, should I enter address C (actual last address) or address A (last address on file with USCIS). If address you advise me to place address C in the form, how do I justify the missing address updates when I moved to B and C? I did not wilfully hold back information, just forgot all about this clause. I am too scared to call the USCIS customer service to ask this fact.