Basically, even if you manage to live with a sense of gratitude, there will be times, perhaps daily or over a longer period, when you revert to feeling miserable due to some trivial matter.

This "miserable" time is often accompanied by the reappearance of old, critical, and negative thoughts. However, there isn't a specific time when this happens; it seems to emerge randomly.

When such times occur, it's best to be aware of them, and if possible, engage in meditation or other activities to activate your energy, which helps to dispel the negativity and allows you to live with positivity and gratitude.

Everyone likely experiences these negative and miserable times. It's important to accept them as a part of life, not dwell on them excessively, and not worry too much about them.

While one could technically say "accept it," explicitly stating that can sound overly serious. It's sufficient to simply not worry about it too much. Ideally, there would be no such times, but since that's not always the case, rather than accepting those times, it's better to simply not dwell on them if they occur, as this allows you to return to a positive and grateful state relatively quickly.

This often comes down to experience. If you're living alone, you can simply try to not worry about it. However, when living with others, mutual understanding is necessary. If you're living with someone and they experience such times, simply acknowledging it with a phrase like "Well, that's just how it is" can help them return to a positive and grateful state. The frequency of these times varies from person to person, but even for those who generally live positively and with gratitude, there will be times when they feel negative. In such cases, there's usually no need to worry too much.

If you have a partner, it's important for both of you to understand that these times exist. If your partner is experiencing a miserable time, you can talk to them, encourage them, or distract them to help them return to a positive state. If they are the type of person who usually recovers quickly, you might simply leave them alone for a while. The best approach depends on the situation.

On the other hand, a lack of understanding in this area, coupled with excessive perfectionism, can lead to problems. If someone experiences even a brief period of misery in a day, they might dwell on it, think "That person has such a terrible side," and discuss it with friends or even argue about it, demanding that they "fix it." This can lead to frustration and even divorce. Ultimately, there is no such thing as a perfect person, so it's more important to not worry about it too much than to demand perfection from others. This is the key to living a stress-free life.

Everyone has a period of time during the day when they feel down, and if that period is too long, they probably won't end up in a relationship or marriage. But, since you feel it's good enough, you're together, so even if your partner has a period of feeling down, it's good to accept it as "that's just how it is," actively engage with them, and try to bring them back to a positive state, or, alternatively, not worry about it too much, just ignore it and wait positively.

The people I become friends with are often quite energetic, and they understand the period of feeling down. They are the type of people who, when they see someone feeling down, immediately approach them with a smile and try to make them feel positive. I tend to become friends with people like that, so while I do have those periods of feeling down when I'm alone, I don't have them as much when I'm with other people. Even so, I do have those periods of feeling down when I'm alone, but since that's just how it is, I don't think it's something to worry about too much. If you're with someone and having fun, you probably won't experience those things as much, and even if you're alone, there are ways to deal with it, such as meditation, so it doesn't seem like a major problem.

Basically, the key is not to worry about it too much.