Nostalgia is a photo filter. It makes the past look warmer than it actually was.

Memory does not store the past, it edits it. The dull stretches get compressed, the ordinary anxieties fall out, and what returns is a warmer and thinner version that you then compare your current life against unfavourably. The comparison is unfair because one side has been processed and the other has not.

When you catch yourself missing an earlier period, try to recall a specific ordinary Tuesday from it rather than the highlights. The full picture is usually mixed, which makes the present look considerably better than it did a minute ago.