Ask yourself the following:
- Can I commit the time and effort to learn these A levels and come out with respectable results (minimum B)?
- Will these results benefit me in the future? (Do you plan on staying in the same roles always? Have you thought of university? Perhaps a change in career? You might have had your mind set on something in the past).
- What subjects do I enjoy? Am I more of a mathematical and logically minded person or am I more on the creative side? Or am I a bit of both?
- When I find these A levels hard at times (which you will, everyone does) - Will I keep pushing for excellence?
After you answer these questions, stack them up and you'll be able to decide for yourself. Don't listen to people telling you to just put it behind you. If it's on your mind, clearly it's bothering you. You know those grades don't represent you. You cringe or feel a slight pain in your chest when others know about it. If you want excellence, go for it?