Make Up One's Mind Meaning
(idiomatic) To decide; to reach a conclusion.
Example: I can't make up my mind whether to have ice cream or cake.â€Ž
1909, Archibald Marshall, The Squire's Daughter, chapterII:
"I was dragged up at the workhouse school till I was twelve. Then I ran away and sold papers in the streets, and anything else that I could pick up a few coppers byâ€”except steal. I never did that. I always made up my mind I'd be a big man some day, andâ€”I'm glad I didn't steal."