Some feel that what should be considered as improvement must be a big difference from before. For instance, if it is based on scores, only by going from 30 points to 80 points is regarded as improvement. However, it is also a kind of improvement even if a day only increases by one minute. Conversely, there can be improvement in the way we think. If we experience similar things, but we feel different today as opposed to how we felt yesterday, that's a type of growth, a kind of improvment.