One of the most nerve-wrecking things about writing is the lost ideas!
These are the ideas that you tell yourself that you are doing to get back to or will writer down later.
There is no ‘I’ll write it down later.’ Later, like tomorrow, will never come. Write down the ideas on the backs of envelopes, voice record them, or on napkins! Write them down—they are evidence that something needs to be written. By you.