The moment I realized I am absolutely gone for this man

I (grown woman, 28) noticed the guy I have been crushing on standing in the distance. He was laughing and chatting with an old man, couldn’t hear anything but just observing I immediately cheered up. I was having a shit morning but seeing him I felt a rush of joy in my heart. It’s insane to me that he can make me feel this way. I don’t understand why or how. I noticed the shift in my mood afterwards (for a while) and realized I’m not too old or above these normal human feelings (I have been quite detached from love for a long time). I don’t want to enjoy it but it feels good and the hope is torturous. Especially because the crush seems mutual but still I could be wrong and things can go wrong.