They are the passive-aggressively snide, and they get off on the reactions they get from others. It's an impotent form of manipulation, and it only succeeds when we feed it with our irritation. Save your hate for someone who is worthy.
Have necessary documentation, patience, more money than clothes. If you have a newer notebook computer, don't bring the box it came in, you would probably be charged import tax on it. Real Thailand is to be found in smaller, less touristy cities and villages, but that is only my personal preference. Metered taxi out of the airport is safest for not getting ripped like a rookie. Night train north is lovely. BYO.