I have many motivations and since I've been working with 3J my progress is gauged by weekly tape measurements, pictures, and weigh-ins. I think a well rounded approach that he requires is a necessity to seeing true progress. Sometimes one thing may be up or down, but the others will prove you are making positive progress.
One major motivation I have is after I've gotten that pump, I see myself, only better. I see 1-2 inches of blood mass on whatever body part I've been working on that day. It's almost like I'm seeing myself in the mirror, but a few months down the road. I've never looked in the mirror with a pump and not wanted to look like that all the time. So, with that being said, for me, "the pump" motivates the fuck out of me. And the worst part about it is that once you are as big as your old pump, your new pump will be even bigger, and it will never end unless I think I'm getting too big. Which at 5'8, and growing up with people a foot taller than me, nothing is going to be too big for me. I've been chasing big since I was a kid.
With a goal to be big as fuck, there's only one way to approach it. Never think you're big. Until I stand next to someone and can literally see that I'm bigger than them, I will always just believe that I'm smaller, and that may be a problem psychologically but hey, If I'm always smaller, I'll always want to get bigger. And that's what keeps me going I think. A mind fucking if you will.