Nostalgia

Nostalgia is denial - denial of the painful present... the name for this denial is golden age thinking - the erroneous notion that a different time period is better than the one ones living in - its a flaw in the romantic imagination of those people who find it difficult to cope with the present. Nostalgia in its primary sense refers to a longing for times past, which can range from fondly reminiscing on events of the past to obsessing so much over a past event that you try and build a time machine out of a DeLorean to travel back to relive the event over and over again. It is not to be confused with a pain in the nose, which would be nasalgia. Quite often nostalgia is employed by an erstwhile privileged class (e.g. White dudes) complaining about being unable to lord it over everybody else in the current era.

Triggering nostalgia
Nostalgia is usually triggered by something which reminds one of a past event, or sometimes when one is doubtful about their present or future situations. People looking back nostalgically tend to see things selectively from a positive aspect, glossing over most, if not all, negative aspects in a memory.

Nostalgia as a political tool
Politicians, usually but not always of the reactionary variety, will sometimes invoke nostalgia for a "golden age" in order to try to roll back changes in the law or culture. A good example was Saint Reagan.

The 2016 Brexit referendum in the UK featured the "leave" side pandering to the kind of people who longed for the time when the United Kingdom colonised half of the world and people could leave their front doors open. This also appealed to that proportion of the population who are still fighting the Second World War and think bringing back National Service/hanging/corporal punishment in state schools (select one or more as applicable) is going to solve all of the country's problems.

Nostalgic
A nostalgic refers to a person who suffers from nostalgia on a regular basis, frequently longing for times past to occur once again. In response to this, the friend of a nostalgic has a choice of a few routes to take in order to "cure" the person from his/her nostalgia:
 * 1) Show the nostalgic a good time to remind him that the future isn't so bleak after all.
 * 2) Remind the person that the past wasn't that great after all by reminding the person of the negative aspects of the time.
 * 3) Say angrily to the nostalgic, "Before! Before! You're living in the past, man! Quit living in the past!"

Examples

 * A "Whenwe"; typically a white former Zimbabwean, or generally any British expat, who has moved to South Africa, and continually bores his new neighbours with tales of the old country, as in "when we lived in Rhodesia", or "when we were back home". It is not a term of endearment.

Reality of nostalgia
Remember how awesome everything was when you were a kid? Everybody lied to you.