"don't talk to strangers"

If 2 people come up to you and start talking to you,
1. do you smile and leave? or
2. listen & then make excuses to leave? or
3. further engage in conversation with them?

"don't talk to strangers"
that's what our parents used to advise when young
but I think I threw my cautions to the wind when I selected option 3

was walking around in jaya jusco supermarket while waiting for someone.
I was the coffee, tea section looking at some green tea
suddenly two chaps appear, also looking for tea for someone elderly who like to drink tea I suppose. So I moved aside lo since I'm not really buying, just selecting & looking.
one of the chap tapped on the basket I'm holding, spoke in mandarin

chap 1 : You know which tea is good? Can you help us choose?
me : haha.. me oso dunno wan o (in broken mandarin)
chap 2 : Have you tried any before?
me : some but I just simply buy, never stick to any particular brand wan wo. So, you both buying tea for?
chap 2 : for the relative in kajang..likes to drink tea

couldn't remember exactly what lead us to continue talking & neither me or them leaving.
one of them is a sarawakian who had no formal chinese yet speak mandarin very well, working and the other want studying at HELP institute. both are housemates. they are humble and nice people (dunno true or not la..but judging from conversation during then)
their names : Ah Lek & Yong Yau
my name : Su Zhen
we chatted for about 10 - 15 minutes, before I make a move to my appointment
and they gave me their handphone numbers, I gave them mine too (dunno why oso)
haha ... for future 'yam char' wo

they might have intentions ... good or bad?
it could be they are trying to sell something / to recruit people
but let's give them benefit of doubt first lo
need not worry, me will be careful wan
but if they are genuine, then there's no harm getting more friends lo

If you ask me
" will you not talk to strangers? "
I'll answer
" depending" or
" perhaps to strangers who "soon-to-be-friends"

you?
" will you talk to strangers? "