I regret not working harder. I worked enough - I got into the university of my choice - but I didn't do as well as I should have done. I suppose it doesn't matter to anyone except me, really. I would have liked to have persevered more with maths, physics and computer programming because I find those subjects difficult. I wasn't very resilient.
I read somewhere that teenagers in general have problems understanding long-term consequences - it's to do with their stage of brain development or something.
I'm a teacher now and there are some kids who are almost unreachable. I have one boy at the moment who is 15 years old and is determined to join the army. He has really low self confidence for a number of reasons and has styled himself as a 'bad boy' so he's not interested in doing well at school. Even in exams he won't write anything. His literacy and numeracy are very poor and I worry about him. He is a sweet boy at times and I wish I could help him more but I'm pretty limited in what I can do, unfortunately.
In my experience it isn't future consequences that motivate most children - it's what's happening NOW. Almost all children are motivated by success in a subject - they all want to do well, even if they don't show it! The boy above has, at times, been very motivated to learn about poetry, of all things, because he had some early success with it. Of course that backfired slightly because he refused to do any other work (bless 'im), but it made him feel good for a little while and gave me something to build on.
If they understand how good it can feel to learn something then they'll go on to learn on their own later. Teach a man to fish etc.
It bothers me as well that anything below a C is regarded as a failure, even by teachers. I've heard some people say 'oh, x is never going to get a C anyway'. A D can be a real accomplishment for some children and it does demonstrate a level of ability in the subject. But why bother trying if the best you can get is a fail?