When I started my freelancing business in January, I set a benchmark for how much money I'd like to make in my first year. I made this amount by July. Once I hit my goal, I was ecstatic. But shortly thereafter, I felt like I'd lost all motivation to work.
I've since discovered that when I'm approaching whatever current goal I've been working toward, I need to set new goals. (For example, I'm approaching my 2018 goals, and am in the process of setting my January 2019 and 2019 overall goals.) This ensures I'm constantly striving to be the best at what I do and not getting lazy once I've hit a goal.