Computer Science is at most times a challenging but rewarding course. Until recent years, there were no computer based courses available for kids or teens, so the majority of incoming students usually come in with very little or no programming experience. Due to this, most students are learning new skills from scratch in first year, with maths, engineering and possibly physics (that's a very slight "possibly") being the only popular Leaving Certificate subjects which relate to the course at all.
Despite this, if you have a mathematical or logically thinking mind, CompSci is a great course to take. There's nothing more satisfying than when something just works the way you wanted it to. When you get into the swing of things, it almost becomes enjoyable to do projects, and to look back afterwards and think "wow, I made that" is a great feeling. If you're a problem solver, it's the course for you.