We really need a word for:

1. The sneeze that threatens but never comes.

2. Overtaking someone on the pavement and discovering they are walking far more quickly than you anticipated, resulting in an awkward jog as you try to get ahead.

3. The humiliation of waving at someone coming towards you and immediately realising you don’t know them at all.

4. The incompleteness you feel when you briefly put down a half-eaten biscuit in order to perform an important task, and then cannot find it anywhere.

Any other gaps we need to fill?