Long reviews can make a listener feel obliged to have a verdict. We prefer brief notes made before the memory becomes tidy: a rhythm that caught us off guard, a passage worth returning to, or a question about what happened in the final chorus.
The point is not to catalogue every record. A short note gives the next listen a place to begin. Months later, the most useful line is often not an opinion but an instruction to your future self: listen for the brushwork after the first solo.
If you want to start, keep it small. Write the title, where you heard it, and one detail you would like to find again. That is enough to make an archive that belongs to you.