I did. 21k I couldn't bring myself to finish on 20k.
I plugged in the numbers for a My Asics marathon training plan to take me through the year, then entered an October marathon (York). Knowing how my head works and that last year was the first I managed to run through the heat of summer I thought having this might keep me going. As its a long plan, over 3 runs a week I guess that's how I came to run long today. Back to the shorter 8 and 12 k runs (with an occasional 5) for a few weeks before another build.