There's an old gringo saying that "Talk is cheap". In Costa Rica, talk holds absolutely no value whatsoever (doctors and pharmacists excluded). Ticos are very polite people and are, and should be, very proud of this fact. But being polite here also means avoiding confrontation - at all costs. In order to avoid confrontation, you lie. Extrapolate, and lying = manners.
If someone tells you they will call you back in an hour or first thing in the morning, it's a lie. If someone tells you they will meet you at your house or at the jobsite at 9 AM, its a lie - but less of one if they actually show up some time on that day. If your appointment with your lawyer is at 1PM, assume your lawyer will be at lunch until 3PM and you will be waiting. I have a formula now: If they say it's an hour, it's three. If it's a day, it's 3 days. If it's a week, it's two weeks. If it's a month, they're being polite by giving you the brush-off without having to say so.
The phrase, "I don't know." does not exist here. If you're asking for directions and someone doesn't know, they will make something up rather than admit that they don't know. If the guy at the hardware store isn't sure the paint is right for the application, he will tell you that it is even though he has no clue. And if you flag someone on their lie - even if it's staring them and, god forbid, witnesses, in the face, you might as well have killed their mother. It will be taken personally. And it will be your fault.
Ticos cannot handle confrontation. Never confront. Do what they do: bury the problem, or go around it, but never confront it. For example, someone working construction on a house next door to me was stealing stuff off of my truck. I didn't know exactly who it was but I knew it was someone working there. Approaching the maestro de obra (job captain) with the problem wouldn't solve anything, because he'd end up taking it personally as me thinking he was stealing from me. So I removed the handle on the spigot on the hose bib on my house that every guy on the jobsite was using to fill their water bottles during the day. Things stopped disappearing from my truck.
Personal responsibility is a new concept here. No one is held responsible for one's actions or inaction. Except gringos. But don't take it personally.