Start this new habit: Block off time on your calendar each month to reflect on your work achievements, plan potential new achievements for the following month, and update your resume.
This should only take about an hour, and that shouldn't be too difficult to find over the course of a month.
1. Reflect on the past month's achievements - Did you increase sales? Did your team win an award? Did you create a new organization system? Did you land a big, new client? Did you get promoted? More things can be considered achievements, but this is a start. Make sure you include HOW you did these things.
2. Plan potential new achievements - Have you had an idea for awhile, but haven't taken time to implement it? Did you come close to achieving a goal last month that you can this month? Are your customers complaining about a specific thing that you can address/improve?
3. Update your resume with your achievements - This process will be so much easier if you do it on a consistent basis vs. every couple of years when you want/need a new job.
I often work with clients who can't remember things that they have done or have not done much beyond their regular scope of duties. This habit will help with that.
It may also serve as a wake up call to do more.