Guys I must say I can relate, and I am sorry for your musical losses, as I have had mine as well.
I have learned that if I have a good riff to take it down immediately, I rush usually. Lol. Somehow I have gotten good enough to where as long as it is recorded I can play it again by ear, I usually do not forget.
Um, but yeah, lately with all the new recording it has been a nightmare. I will get this awesome riff and find I never hit record as well, or get this great solo going (Which is very rare for me) and once again, did not record, or accidentally delete it by double clicking "Stop" in Guitar Rig.
It drives me insane, Lol. I find that you just have to be very precise and make sure you get it recorded. I cannot tell you how many riffs I have written that I will remember the notes but forget the timing/rhythm on, that is another reason I keep the recorder handy in Guitar Rig.
A good example is a new song I am working on, I am using arpeggios, letting those notes flow, ring out, but there is awkward timing to each part of the song. I have not figured out it's exact timing in music standards, but in my head it is like going from 4/4 to 6/8. That is what I meant by my new stuff is more complex than my old.
Anyhow, I like this topic, Lol. Mainly because I think we have all faced "Musical crises" before.
Peace out, GuitarAnatomy.