Here are a few videos I like that may resonate:
Alan Watts - The Dream of Life (3.5 minutes)
Ken Wilber “I Am” pointing out instructions (7 minutes)
(See also: a version of the Alan Watts quote with footage from Inception, and another version with music from Nuages)
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Personally I don’t find “This is a dream” (when I’m physically awake) to be helpful, but “This is dreamlike” works well for me. I also created a Spotify playlist called Dreamland with songs about dreaming, the bardo, and similar material, and sometimes I walk around listening to that, and it helps to cultivate that sense or perception that waking reality is dreamlike.