Question: why do we forget most of what we dream at night after we wake up?

Anaïs Pujol answered on 16 Mar 2015:

That is not true at 100% for every one. A lots of person does remember their dreams, it is a question of practice.
When you sleep you have a phase call ‘Rapid eye movement sleep’ and you do have four or five period of it during your sleep for a 20–25% of total sleep. Majority of it occurs the morning. The dreams that you remember are the ones which happen the morning, and you need 10 min to delete them from your brain. If you want to remember about them, write them up when you wake up.