I'm 51 and through injuries from an accident and weight gain, would've had trouble breaking 25 for 5K two years ago. My accident was at age 42 and I'd been running around 19-19:30 for 5K at the time; the fastest I'd run since the accident was 22:45.
At that point I took a good look at my lifestyle and didn't like what I saw, particularly the extra weight and I was still eating like I was training for marathons in my 20s. Through cutting back on snacks and portion size, I lost 10-15 lbs and found that running was easier for me, and eventually dropped 25 lbs. By running 20-25 mpw on 4-5 days a week training and concentrating my quality efforts on tempo runs and strides, I ran 20:13 for 5K on my 50th birthday and thought I could break 20 again, something I never thought I'd do again.
But I found that when I tried to train more often, my chronic injuries kicked in, and between that and the time and energy commitment needed to train at a higher level, it never quite got done. I have some developing arthritis in the knee of the leg most damaged by the accident, and I want to run for as many years possible, and I've decided that it's not worth it risking not being able to run at an earlier age for the little bit of time it would take to drop my time into the 19s again at this age. But perhaps you're healthier and would be able to sustain the training, I wasn't willing to run the risks.
Also, if you're 185 lbs at 6-01, you probably could stand to lose a little bit of weight. I'm 5-11 and dropping from 190 to 165 made all of the difference in the world. Last spring I didn't run for 6 weeks because of a broken bone in my foot, and I'm sitting at about 170-175 now and can feel the extra baggage, and I'm trying to watch what I eat a little more so I can feel better in my runs.
I've settled into a late middle-aged routine of running 15-25 mpw on 4 days a week, one tempo/interval day and one long run of 8-10 miles. Through this I'm able to run consistently in the 20:30-21:00 range, and I can live with that.
Good luck finding your own path!