The Luas is frequent which makes up for a lot, but the schedule is given as (every X minutes) and often misses that due to sharing with road traffic for large parts of the track.
Still better than bus eireann, where if you're getting on in the last 25% of the route, the timetable is often every hour, +/- 30 minutes, which means there could be a bus at any time and it's not likely to be the scheduled time.
As you stare deeper into the rising, darkening mist of the pint, you edge ever closer to it. Until the darkness obscures all else in your view.