That was a very common occurrence when I got sober. I did so very publicly in a small town where everybody knew me. It was difficult in early sobriety until I was finally able to understand that these people weren't alcoholics. They really had no concept of what it was like. Many of them believed I just decided to quit drinking one day and that was that. Once I was able to realize that they weren't judging me, but that they just had no way to understand how difficult it is for an alcoholic to quit, then it stopped bothering me. But it probably took a year to reach that point.
About 14 months into sobriety, my closest friend that I had known since I was 3 years old asked me how much longer I wasn't going to drink. I told him I was shooting for forever. He seemed shocked and said "But it seemed like it was so easy for you to quit." I told him "Quitting drinking isn't the hardest thing I've ever done, it's the only thing I've ever done." And he got the point.
Getting sober seems like a constant battle at first but it's mostly fought within your own mind. I used to think it was very evident to everyone who I came into contact with how much of a struggle it was for me. But it's mostly invisible to casual acquaintances.