Education
Education is arguably one of the most important aspects to consider when applying for a job. Depending on how much education you have received in the past, the quality of the education, and the levels you attained in exams and the like may have a considerable effect on the types of job you can go for. It is unlikely that somebody who has three GCSEs would be able to get a job as a television executive as they would not be qualified, and it would be equally as unlikely for someone with a PhD in Structural Engineering to be able to get a job working in a packing factory, as they would be overqualified and unchallenged.
As such, it is important to consider whether you need re-education in a certain area, whether you need to re-train in a specific thing, or if you need to take further education and/or training. If you have A Levels in chemistry and biology, that would be useful background knowledge for a forensics course at university, so if you wanted to become a forensic scientist or something similar, then it would be easier for you to do than if you didn’t have such experience or qualifications.
There is no shame in education as an adult, either. Age is not respective of ability, so if you decide you want to follow a different career path later in life, or just to learn something new, there is nothing stopping you from doing do at all.