In all one's lifetime it is oneself that one spends the most time being with or 
dealing1 with. But it is 
precisely2 oneself that one has the least understanding of. 
 
When you are going 
upwards3 in life you tend to 
overestimate4 yourself. It seems that everything you seek for is within your reach; luck and opportunities will come your way and you are overjoyed that they constitute part of your worth. When you are going downhill you tend to underestimate yourself, mistaking difficulties and adversities for your own
 incompetence5(不适当). It's likely that you think it wise for yourself to know our place and stay 
aloof6 from worldly wearing a mask of 
cowardice(怯懦,胆小), behind which the flow of sap in your life will be 
retarded7.
 
To get a thorough understanding of oneself is to gain a correct view of oneself and be a sober realist -- aware of both one's strength and shortage. You may look forward hopefully to the future but be sure not to expect too much, for ideals can never be 
fully8 realezed. You may be 
courageous9 to meet challenges but it should be clear to you where to direct  your efforts. That's to way so long as you have a perfect knowledge of yourself there won't be difficulties you can't overcome, nor obstacles you can't 
surmount(克服,战胜).
 
To get a thorough understanding of oneself needs selfappreciation. Whether you liken yourself to a towering tree or a blade of grass, whether you think you are a high mountain or a small stone, you represent a state of nature that has its own raison detre. If you earnestly admire yourself you'll have a real sense of self-appreciation, which will give you confidence. As soon as you gain full confidence in yourself you'll be enabled to fight and overcome any adversity.
 
To get a thorough understanding of oneself also requires doing oneself a favor when it's needed. In time of anger, do yourself a favor by giving 
vent10 to it  in a quiet place so that you won't be hurt by its flames; in time of sadness, do yourself a favor by sharing it with your friends so as to change a gloomy mood into a cheerful one; in time of tiredness, do yourself a favor by getting a good sleep or taking some 
tonic11(补药). Show yourself loving concern about your health and daily life. As you are aware, what a person 
physically12 has is but a human body that's vulnerable when exposed to the elements. So if you fall ill, it's up to you to take a good care of yourself. Unless you know 
perfectly13 well when and how to do yourself a favor, you won't be confident and ready enough to resist the attack of illness.
 
To get a thorough understanding of oneself is to get a full control of one's  life. Then one will find one's life full of color and flavor.