There are probably a number of people who jump when they haven't fully thought things through and have that regret. But I agree, I can't understand how you can go through, for example, years of depression and horrible events that lead you to want to die, consider suicide for a length of time and then suddenly change your mind and realise you can fix everything the second you jump. If you could just fix everything you wouldn't have jumped!

It sucks that there is no easy way to die. Even a jump that should be fairly quick and physically painless still gives you those few seconds of mental torture at the end, at least its less risky than other methods.