it's 19 years since I flew around the Highlands and Islands and 14 years since I was last upside down
I think the use of the phrase "ticked that box" is quite telling. The danger of that approach is that you will remain unfulfilled. Ticking off an endless series of boxes and passing immediately on to the next does not lead to satisfaction in life. I know some people who are retired on a good pension and are literally ticking off places in the world. But their travels teaches them little or nothing either about the places they visit or more importantly themselves.
Each activity should be an opportunity to learn something. As an example, flying to the highlands will stretch you in terms of planning the journey and in terms of your skills, due to the wx and nature of the territory over which you fly. You will have to really think about the trip. The planning may be an end in itself but what do you do when you arrive. What do you know or learn about the country you have arived in and the people who live there. In that sense the flyign can be a means to an end; it get you to places you would not go if you hade to drive.
If you liked aeros, then why not work on polishing the necessary skill. Not only wil that be a challenge for you to perfect say a loop and to understand what is happening to the aircraft but you will be pleasantly surprised how that feeds back into your basic flying skills.