Specifically, consider whether building one or more $X,000/month apps can help you achieve a similar lifestyle that a $5M payday would bring. For me, I want the independence to work on what I want when I want, have the flexibility to take breaks to spend time with my wife and future kids, take a nice vacation or two each year, etc.
This will obviously depend on your life situation, your savings, your spending habits, etc, but for me, I think I can achieve that with $4K-$5K profit/month. And making that much via a few niche web apps is much, much more likely than selling for a few million dollars down the road. (I currently have two ~$1K/mo web apps and am still at my day job for the moment, so getting to that point from where I am should definitely be doable.)
If this appeals to you, I recommend checking out Rob Walling's Micropreneur Academy, which is a great start for anyone going down this route: http://www.micropreneur.com/