be down on oneself: I was once deeply down on myself at the time that I found I am very interested in doing ghost pranks

precursor: 

Rhythm and blues was a precursor of rock music. 

Small tremors may be precursors to big earthquakes.

The Office of Strategic Services in World War II was the immediate precursor of today's Central Intelligence Agency.

A protein precursor, also called a pro-protein or pro-peptide, is an inactive protein (or peptide) that can be turned into an active form by post-translational modification, such as breaking off a piece of the molecule or adding on another molecule.

get in touch with: I finally got in touch with that professor whom I adore

come to mind: A great new idea suddenly came to mind

elicit: This topic can elicit some of my past events