Getting lost and traveling go hand in hand and everyone who ventures out into the unknown has experienced asking for directions from a total stranger who barely (if at all) speaks your language. You would assume the local you are asking knows their way around, and you heed their advice which leads you in... the completely wrong direction!
You trusted their advice and after 20 minutes of wandering around, you wondered if they had an evil motive and were trying to get you lost on purpose, or simply made a huge mistake. This is where the RULE OF 3 comes into play.
While backpacking in Mexico, everyone in the hostel soon realized that they had been given the wrong directions numerous times, and in order to save a little sanity, they would need to ask multiple people for the same directions. The actual number differs by country, but the rule in Mexico is the rule of 3, and sometimes 5.

Here is an example of how the process works:
- Venture out with a destination in mind.
- Ask one of the first people you see who looks helpful.
- Wander one block in the direction they pointed.
- Find someone else to ask for directions.
- If the answer was the same as the first, continue one more block that direction. If it was different, head one block in the direction the second local pointed in.
- Ask one more friendly stranger how to get where you are going, then stand for a second and ponder all three sets of directions.
- Take a general average and head that way or choose the one person you felt was most confident and trust them.
TIP: When there is a language barrier, be sure to know the translation for the following words: left, right, straight, and blocks. These will get you closer to your point of interest by making sure you aren't totally screwing up.
When all three sets of directions don't seem right, head towards a more trustworthy source of information such as a tourist info center, hotel concierge, detailed map, or just give in and pay the taxi. Chances are you are headed somewhere none of the locals ever go.
TIP: Walk one block (and maybe two) between asking locals simply to be polite. It would seem very rude to ask someone for directions and then immediately ask the next person on the road showing that you obviously don't trust the first person.
The lesson to learn is that most people are over-generous to lost travelers and want to help in any way they can. If you ask someone for directions in Mexico and they don't know the correct way, they will not tell you they don't know but simply give you the best guess they have.
Well thanks, but no thanks. I would have been better off with a simple "no". People's generosity has led me astray numerous times which is why I now usually will stretch the rule to a "sometimes 5."