I have always hated air law, and had little capacity for it. If you look at my CPL exam results: a line of high 80s and low 90s, then 76% for air law. I don't have record of my PPL(M) and PPL(SEP) results, but my memory suggests that they were also both scraped minimum passes.
For me the textbook was largely irrelevant - the best learning and revision tool was a huge pad of fine-lined A4 paper and a box of coloured biros. Then made my own notes longhand, and again, and again, and again...
.... it's the only way I was ever able to memorise such a tedious mass of detail, for which I have little affinity.
In reality I know this material is important, but my ability to recall it isn't - I need to know that there are rules about these subjects, and where to look them up. For about 95% of it anyhow, the other 5% is usually interesting enough I actually remember it.
G