Directions: an ethical dilemma

I have a dilemma.

On the one hand: I hate asking for directions. For instance: this
summer when Mr. TA and I were on vacation in Vienna, at one point we
were walking around the same block multiple times, gawking at the map
and at the street signs, totally unable to find the architecturally
significant building we were looking for. A man came up and asked, in
English, "Do you need help finding something?" And I said "No,
thanks." Without even thinking about it. I think it's some kind of
desire to seem in control of things, and to avoid getting emmeshed in
a discussion with a stranger. Both very stupid reasons, I know!

On the other hand: when I see lost tourists in DC, I have a strong
urge to offer them directions. I like the idea that they will have a
positive interaction with somebody in DC.

BUT, is that really it? If I were them, I would not want me to offer
me directions. So by doing it, am I really just engaging in a power
trip, making myself feel superior to the dumb tourists?

I thought of this the other day and felt chagrined. So, the next time
I saw lost tourists I ignored them. This became harder and harder as
they walked around Dupont Circle in the same direction as me,
squinting at the street signs and asking each other, "Does this one
say New Hampshire Avenue? Does the next one say New Hampshire?"

Arghh! I could easily have told them which one was New Hampshire.
But then, they would eventually find it if they kept walking around
the circle. What do you think--should I offer tourists directions?
Or should I perhaps take this as a sign that I should not be so
stubborn about asking for them myself?