It's very easy to get obsessed with checking your Google Adsense account. It only takes a few seconds to click and refresh your account. The temptation is to keep a window open and check every few minutes. This is just a waste of time and energy.
If you can discipline yourself, you should not look at the statistics more than once per day. After a while the number of daily impressions is reasonably predictable. Clicks and earnings per day are totally unpredictable, the table below illustrates this point (please note these are purely theoretical numbers and bare no relation to my actual numbers):
This table plots click through rate (CTR) against number of impressions and shows the chance of getting zero clicks. For example if you have a CTR of 2% you have a 0.23% chance of getting zero clicks after 300 impressions. The table shows that it's only when you get towards 1,000 impressions that you have virtually no chance of getting zero clicks.
I see many questions similar to: "I've had 300 impressions but no clicks what's going wrong?". The table shows that it can happen just due to variation. You need a large number of impressions to smooth these variations.
In conclusion, I try to only check my statistics once per day and try to measure progress by the month.