Hi @juan1 ,welcome to the forum.
This is precisely why I never try to be creative when it comes down to encoding words.
A better approach would be to use rhyming words/Homographs/familiar associations etc.
I use actions/creativity only when nothing else works,as a last resort.
Usually,one should’nt try to memorize those abstract words,but in ur case it’s book titles,which I feel is a valid reason. I’ve tried to decode your word list,see if it helps.
Lies = lice comb.
Potential = Pot with an Energizer battery(as in Potential Energy).
Change = a dollar bill with some coins on it(as in - keep the change).
Thoughts = Statue of ‘Thinker’ or the Egyptian God Thoth.
Skills = Skillet.
Priority = reminds me of the late comedian Richard Prior.
Opportunity = (wh)opper burger with a tuna can.
Association= An Ass(donkey) or a (girl with a fine behind) at a station(railway/gas).
Lesson = bowl of Lasagne.
Temporary = bowl of Tempura shrimps.
Excuse=Think of an Ex-relationship(even a childhood crush would do).
Also,here are links for mnemonic images of filler words.
Hope this helps…cheers 