For myself I have to admit, I have about a 2 year attention for most things, then I get bored. The boredom usually comes from a lack of challenge as I master whatever it is to the point I want to take my expertise.
There are some exceptions to that so far in my life. One is auto racing... But only as a partial exception. I started with drag racing 1yr, then auto cross 1yr, then road racing 4yr... Got to the point of considering a competition license and then switched to working Tow on the rescue crew 4yr, now I do race control in my 3rd year of that. Still involved in the same world, but different aspects.
The other exception - which really is an exception is running. I've been running for 5 years now and it has become a part of who I am. I'm a runner. I run and train all year long. I pick races to run as an excuse to keep running... I need some outside goal to give me the excuse to take the time for myself when I run. "Honey, I have to get up at 5am to run 20 miles because I have a race in 3 weeks." I would do it anyway, but having the goal helps :) i get into less trouble that way. When I don't run I get depressed and grouchy.
So, what does this mean for this awkward bird? Well, according to his statistics I have a 20% chance of actually hitting my initial goal and earning a PPL. I think if flying was just another thing (cycling for instance) I wouldn't stand a chance. However, I don't remember encountering anything else in my life that has the combination of joy and challenge that flying has for me. The hidden world of aviation, the physics of flight, the aspects of flying an airplane that aren't easily articulated in numbers or words, but have to be seen and felt and internalized before you can become a good pilot. The responsibility and control, the PIC is fully responsible and fully in control of all decisions regarding the safety of the flight. Not to mention the thrill of take off... The beauty of the world from above, the aspects of being part of a brotherhood that knows the air almost like birds do. Conquering fear of turbulence and steep turns (heck turning at all scared me my first lesson). I can go on and I'm sure I will again and again :)
Given my current attitude and interest in flying (you can call it obsession) I think attention span will not be an issue for me. He says I have the skill and focus to be a very good pilot too... I love to do two things... 1 learn and 2 be really good at what I learn. This seems to have good potential.
Bottom line after much rambling... I am planning on being an exception to the statistics. I plan to take things further than PPL too. I plan on getting instrument rated and a commercial license. Then retire from this high tech world and make my livelihood my passion, fly people on sight seeing trips, aerial photography, search and rescue... None of which pays well at all.. But at that point it's not about pay, it's all about love. Yeah, I've got a crush on flying... And I have to admit, I like it :) I hope this gets the chance to develop to love... I can't think of a better way for me to go off into the sunset than on wings.