I've been exercising 3 days a week since last October. Prior to that, i hadn't exercised or played sports for close to 5 years, so that combined with getting older caused me to gain 20 pounds more than my ideal weight. I'm 5'10" and with my frame, i prefer to weigh between 150-160lbs. My problem areas are my face and stomach. For whatever reason, i can have skinny arms and legs, but a chubby face and stomach hah hah, so i really wanted to change that. I didn't like how i looked in pictures and i also didn't like feeling easily winded.
It's easier for me to stick with exercising because i have worked out regularly for 1+ years at a time before, so i'm used to the relatively long-term commitment. This time around, I started off with weightlifting and cardio (treadmill/elliptical) combined with a relatively strict diet. I ate mostly lean protein, low-starch veggies, and low GCI fruits. I cut most carbs out of my diet, but i did give myself the weekend to cheat slightly. I am currently not as strict with my diet, but that is ok with me because i'm still in good shape. I have lost the 20 pounds, and now i've put on about 10 pounds of muscle.
It's relatively easy for me to motivate myself because due to my work schedule, i have all morning and most of the afternoon to make time for exercising. I imagine that people with a more traditional 9-5 work schedule find it more difficult to make time for exercise because after a hard day's work, people probably just want to relax. I find it easier to work out before work, but not if i had to wake up at 6am in order to do that. And if you have a family with children, making time must be ten times more difficult.
Anyway, it's all about making time for it. If you have the time, then exercise at least twice a week! Start off with baby steps. Obviously it's not just about appearance, but it's about your overall health as well. For some of us that are getting older 35+, it's more important than ever to stay fit.