Don’t know what to do?

I was at a concert and this cute guy noticed me. He went straight up to me and was standing really close beside me. We were touching arms and he bumped into my bag and he was staring at me the whole time. He was even pulling his chest higher to appear taller. We were in close proximity for hours glued at the side of each other but l was too shy to say anything to him or look at him and he didn’t talk either but was just staring. l felt this warmth of comfort from him when he was near me. Something was pulling me towards him. Now l can’t stop thinking about him and regret not exchanging numbers or any form of contact details. Should l feel guilty for not doing anything as l feel like the man should ask for those details. I’m not sure if l will ever see him again.
Don’t know what to do?
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