Just got in under the wire with my first 55 ever! And I did it the hard way: 16 birdies, two pars, no eagles. Missed eagles from 18 feet on #4 and 6 feet on #12, and was on the green but in the wrong zip code on #8 and #18.
I made a bad mistake on #15: apparently (going by the scorecard) my tee shot, which settled 10 feet below the hole, was actually off the green. I played a normal putt and came up 8 inches short.
But all is forgiven now.