Dang, I became a LPR in June 2017 and I had to go back to Mexico in Oct 2017 to give up my apt, last paycheck, etc.. Before that I went back to my home country and then I was in the US for like a couple hours or so for a few month - I crossed the Laredo border with my US visa to get some shopping done and this was all in 2016/2017. Damn - now I gotta remember all those dates!