'Giving up being good at rugby to play football'.
Firstly, as a few have already said, surely that's not your 'biggest regret'. If indeed it is, sadly it's not actually a surprise at this stage. Secondly, the sentence doesn't make sense. You can be good at one thing whilst still doing something else. Thirdly, and this is conjecture on my part, but I genuinely can't imagine him being good at any sort of physical activity. How are you meant to play rugby or football with Sideshow Bob bad boys on.
Also, your shoes are fuckin mawkit. Get them washed.