I'll give you a tip, if it helps. So, early on in my career, I'd be in big companies with big products. The little feature or whatever I'd work on just didn't seem all that important to me. I didn't care what my managers thought. I didn't care about the company. The stock price didn't matter because I only had a few measly shares worth nothing. Everything about the situation felt like a waste of time. I'd stay up late at night working on side projects, only to be tired at work and, again, too tired to complete the side projects I felt were more worthy of my time.
Somewhere along the way, I decided I wanted to make a product for myself. Something complete, contained, and ready to release to market -- good or bad. It was that process of trying to make something stable, complete, and market-worthy that let me understand the grind. The last 1% is so much more awful than the first 99%, and it's in those details where all the "mental gains" are made.
Today, there is no shortage of opportunity to get a feel for what it takes to make a complete product. Whether it's the app store, a functional web site, or just anything that gets, oh say, 1000 users. You just need to go through the abuse of completion once to get an appreciation for the grind. Once you know what you're in for, then you'll be more selective about what to start. Moreover, the end goal will make the grind seem like a logical step instead of endless toil -- this is where the grind is understood and appreciated.
Just my opinion and experience! Hopefully it helps.