I believe it is just a crush or obsession from the gal as it is
really difficult for 2 persons whom do not know each other to fall
in love just like that.
It happened to me quite a no. of times in Fast Food Restaurant,
Food Court, Public Transports, Bus-Stop, Shopping Centres etc but I
am still looking for the right one 
There are cases where the gals I met at bus-stops did notice me
& guess what,
1. She will start to comb/brush her hair near to her ear using her
hand (usual way that all gals do leh)
2. She start to pretend to walk near & near to me!
3. When she is near to me, she will catch a gimpses of me as often
as she likes till her bus comes!
4. It attracted the attention of the guys who is wondering who am I
to those gals. by the way, I am not a Casannova or thing like
that.
If anyone out there interested to know other stories that happened
to me, well I am willing to write it down here.
I am just wondering why those gals behave this ways...I can only
conclude that it is a crush on me (so thick-skinned, sorry for
that)
Other than that, I cannot offer any good reasons for their
behaviours