Guy I haven't talked to in 11 months texted me, wtf should I do?

long story short i (21f) was in a pretty rough situationship with a guy (22m) for about 4 months last summer. we obviously both liked each other and got really close, even talking to each other about very deep and personal parts of our lives, but nothing ever went beyond casual flirting. i was too awkward to make a move and he was always weirdly nervous whenever we met in person. we got into a big argument last October, and up until this morning we hadn't talked since, and shortly after he started dating a mutual friend of ours (19f). they broke up shortly after, and i recently talked to the friend and from what she told me i can tell that she didn't really know much about him, which i find kind of funny. i was really hurt by the whole thing and never even tried reaching out for closure. last month, i saw him at a concert (we're both metalheads and the local scene is small so i honestly was expecting to see him). i waved at him and he replied very hesitantly, but we didn't talk. that kind of reopened the wound for me, and made me think about him a lot. this morning, he randomly replied to an instagram story, and used it as an excuse to ask me how my life was going. he was oddly nice about it, considering we left off on bad terms, and that left me really confused and unsure what to do. even though i miss him, i'm still angry with him, and texting me out of nowhere after 11 months of silence is really odd to me
Guy I haven't talked to in 11 months texted me, wtf should I do?
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