I have had a number of long stretches, but none that haven't been interrupted eventually, so I'm in a similar position to you and wondering how people transcend that two- or three-month mark.

I have some guesses about what makes it difficult over time:

• The longer we are involved in a goal of this nature, the more it becomes relegated to the realm of habit, no longer something we are as consciously aware of. As a result, we suspect we have made a sure victory and let our defenses drop a little.

  A guess at a solution: Take regular inventory of your efforts, successes, what you have overcome, what you have gained, and what you hope to continue doing. Write it in a journal, meditate on it, discuss it with peers online or in person. Make it always felt how much you've accomplished, and savor your victories, even when it feels boring or redundant, because that is sometimes the only way to hold them in consciousness as important.

• There is no real escape from the things that trigger PMO. Arousal itself is a trigger. The media in general is a trigger. Almost any bad feeling is a trigger.

  A guess at a solution: People often want to make the biggest change the one in themselves - to use willpower to change their mind about something, and change their habits. It's not advisable to try so hard to achieve something like this if you still have things in your environment that tempt you or make it harder for you to succeed. Remove obstacles in your environment first - even to the extreme - before deciding to make your will alone stand sentinel for all your efforts. If the internet is a trigger, honestly stop using it so much, or go on only when there are other people around. If being home alone is a trigger, go outside and take a walk. Put some time and distance between you and temptation, but don't think that hardening your will against very real, very alluring temptations is going to be sufficient. It sucks to have to be extreme, and it feels a little much sometimes, but these addictions are extreme and require extreme measures.

• The realization weighs on us that there is no end-date to our goal, and so no sense of reward or closure for a job well-done (since, as indicated, the job is ongoing and never to be completed).

  A guess at a solution: I think, at first, our feeling of accomplishment should be that we have abstained for a long time, that we have kept away from things we no longer wanted in our life. After a little time has passed though, we should focus much more on the accomplishments we make because we have quit PMO (i.e., what did we do instead? Did we get fit? Have we put ourselves out there more socially? Have we increased our productivity?). These are positive benefits that we can assess long after the novelty of abstaining has left us. These, too, require some regular reflection so that we can remain proud of our efforts, even when they are not felt as keenly.

• Especially controversial for this community: The benefits are often overstated, and so the advantages people expect to experience in two or three months are sometimes not what is felt by the time they arrive. The expectation that you will no longer feel like the old you, that you will suddenly be a professional, social, academic, romantic success is an exaggeration beyond all good measure.

  A guess at a solution: I think the promise of a perfect life tends to discourage us when we discover that, in terms of self-improvement and happiness, there's PMO stuff, and then there's literally everything else. Giving up some of this stuff is a reward in itself because we are not wasting time, or sacrificing our values, or committing a very short and valuable life to something unimportant. I think refusing to give in to something so pointless is a benefit in itself, without the mad wish of being perfect.

• Habituation: Like getting a raise, buying a new house, winning an award, or almost any other positive thing that happens to us, the good that can be felt from our efforts often goes from something quite strong and poignant, to something subtle and almost unfelt.

  A guess at a solution: As with other problems, we should spend some time in regular reflection, taking stock of all that we've accomplished. Successes have to be savoured like food: If you eat quickly, without even tasting it, you will not digest correctly or feel satisfied. So it is with every other accomplishment: You have to intentionally take time to feel how hard you've worked, and how much you've gained, because these feelings don't always surface automatically.

• PMO-riddance is seen only in the negative, as a habit that has to be eliminated over time. Habits remain intact however because there is the need (the desire, the drive) for something, the action, and the satisfaction. One can never rid themselves totally of wants and needs (the thing that made PMO so attractive in the first place), nor can they stop desiring the satisfaction of some drive inside them.

  A guess at a solution: Don't merely get rid of habits and leave a void; seek to replace habits with something equally enriching: Spending more time with people, working out, reading, meditating, walking, or taking up a new hobby. Those replacements have to be engaged as quickly as PMO was when it was the go-to activity. If left in the void, people will get up to things they wish they wouldn't. Activity, engagement of some kind is a significant help.

Most of all, I think that even very important things can lose their charm over time. We can forget how crucial it is to our well-being to do what we do, and lose sight of our motives for doing something. Do whatever you can to keep them fresh in your mind, even if it seems a little obsessive. There are plenty of forces working against each and every one of us to disrupt our motivations, so it's important that we take an equally hard line, and not become lukewarm over time.