Much as the others have said; i'll add : Being 14, you may or may not know this, but you never need to get 100% in a class in School, just the A (although striving for 100% does no harm). Generally a good University will ask for something along the lines of AAAB, or AAB from your highers - assuming the system in Ireland is similar to that in Scotland. So, AAAB, with two of those being Physics and Mathematics should all but guarantee entry to almost any University in the UK & Ireland (perhaps no Guarantee for Oxbridge, but still a good chance).
Dont worry about your career at the moment though, use it as an inspiriation to do well in School. Most people consider School nothing short of a bother - and most of the time it is - but just remember that you are there for the grades you get, the School system is offering YOU free oppurtunities, and if you enjoy Maths/Physics, then getting good grades won't be a problem at all; 10 years from now you will be massively relieved that you actually left School with decent grades, it makes your life a whole lot easier.
If you need to be grounded, consider that another 11 or 12 years will pass before you even have a shot at being a reasearcher. For now, just do whatever it is that you enjoy, don't run before you walk lest your passion gets broken from the fall.
You could check some of the Universities websites and take a look at the Physics departments, they are often a good source of information and inspiration - as are their Prospectus'. Most Universities will have a form which you can fill out on their website, and they will send you a free glossy Prospectus which you can read through. That will give an overview of what grades you need, what you will be doing at University and what you can do once you leave University.
One last thing : High-School Physics and Mathematics can seem boring compared to all the advanced and exciting stuff you can learn about later - but there is no chance of having the oppurtunity to explore all the exciting stuff unless you have perfected all the basics! The more comfortable you are with Maths, the easier Physics will appear. Working with fractions, surds, roots, linear graphs, understanding and re-arranging algebraic expressions/equations, trigonometry (especially that) etc - all that stuff you will be learning now and in the next couple of years, make sure you are good at it all and everything else will seem like a piece of cake. If your teachers arent explaining things well enough, make them explain, never be afraid to ask questions - those who ask questions are usually those who will do best.
I'll buy you a Guinness when you graduate.
