This is a story about setting expectations...
The way that I've ever achieved anything is by setting my expectations, such that I'm aiming higher than I need to. Isn't there an idiom which says that if you want to reach the moon then you should aim for the stars? I hate stupid trite contrived quotations, but I've always found that pessimistic estimates are the best ones, although somewhat depressing at first.
Rather than setting myself a goal of 28 days sobriety, and celebrating at day 14, instead I started at some point in September and I'm planning on continuing into November. By setting myself a goal which is far harder than a simple month of sobriety, I have assured myself at least four weeks to give my liver a chance to recover, and to lose some weight. By over-achieving, this is a much more desirable outcome than an agonising crawl to the finish line, with the final part of the journey almost unbearable.
To celebrate so-called milestones like 'halfway' is setting yourself up for failure, because progress is nonlinear, and the difficulty of any given day is not comparable to any other day. Some days will be hard and some days will be easy. It is highly likely that the closer you get to one of your milestones, the harder you will find the task in hand.
In fact, having a time-based objective is probably of little or no use. My present objective is to improve my health, lose some weight and re-assert control over a substance - alcohol - which had crept its way far too habitually into my daily routine. If it takes me 6 weeks to achieve that goal, 6 months or 6 years, it doesn't matter, because the end result remains as desirable as ever. There's never going to be a problem trying to be healthier and keep the waistline under control, as well as not allowing the demon drink to become an addiction.
While I applaud anybody who has "Go[ne] Sober for October" my own personal objective was to aim higher than a simple month of abstinence from alcohol. I have less than a week to go before the October 31 "end" of the sponsored charity event, but I'm acutely aware that this is the period when many of those participating in the sponsored sobriety might decide that "one little drink won't hurt" and thus undermine any achievement they hoped to gain. Nobody really cares whether you cheated or not. As is often said: the only person you're cheating is yourself.
So, although by conventional linear milestone measurement, I'm easily way past halfway, I prefer to think pessimistically: I'm nowhere near the end yet. I find it easier that way, and I find that I am more likely to achieve success.
There will be more steps. Six more, to be precise, but do not assume that all steps are equal, and remember that you might have to repeat steps - progress is non-linear.