Writing useful commit messages when working alone

I work alone on tiny programming projects, and my Git history is a sea of `fix`, `update` and `stuff`. When I return three months later those messages tell me nothing. I'm trying a habit of writing what changed and why: ‘Handle missing CSV headers’ instead of ‘fix import.’ How much detail is useful for a solo developer? I'd like a history I can scan without turning every commit into a miniature essay.