>>1819654If you keep with it, it's pretty rewarding to see how your fitness changes over time.
I live on the top of a hill, and there's an easy way up, and a hard way. And as kind of a benchmark, I'll ride the hard route about once a week, just often enough that I don't forget the details of what last time was like.
And each year when the weather breaks, it's about the same. At first I can't do it in one shot. Then I can do the whole thing in lowest gear, then I'll start upshifting where the grade changes near the top, etc. Eventually I'm able to reach the top, and my breathing is still controlled. That's when I know I'm fit.
It reminds me of some old Jobst article (or newgroup post?) where he talks about how to become a faster rider. That's not my aim, but the advice was similar. Ride the same loop often enough, try to push yourself a bit harder each time. No clock, no meters, etc--you'll know if you get it.