Memory triggers are necessary tools for memory-gapped people like me. It’s too bad though if an experience you don’t want to forget ever is not concrete enough to have a memory trigger. (All this memory blah reminds me of Eternal Sunshine of the Spotless Mind.)
…That’s why sometimes we must consciously create MTs.
A perfect example is a diary, or a small notebook always at an arm’s reach for the fleeting thoughts, like this. With timestamps of course.
And for a guaranteed daydream: do not focus.