The symptoms r different for different peoples....
You realise you love that person but you understand this love isnt like a best friend thing. You want to be special for that person. You give a special place for that person. You dont have to express your love like every other person. Every person expresses their love in their own way. What you call love is your love. Not mine not others.
I don't know much about it may be when you want to know more about the person u like , in my experience I hated myself to love someone who is already on love btw it's just butterfly thingy heart started to race faster
Ive never understood the butterflies thing