Allow me to retort.
1)The element of surprise was only at the very beginning of the
intervention of China in the Korean war. It was not like the war
finished 3 days after China's intervention. The actual war went on
for far longer than that. Besides, creating the element of
surprise IS part of war strategy. 
The element
of surprise do not fall down from the sky.
2)Chinese soldiers did outnumber their enemies, but Chinese
army had to use FAR inferior weapons. They even had NOT a
single aircraft. Do you think many other armies could have achieved
what they did under those circumstances? Plus they were practically
up against the UN, being led by the victorious WW2 nation USA.
3)"retain status quo"? Incorrect. When the Chinese started to
intervene, North Korea (NK) was ALREADY overrun by US, with the UN
soldiers almost reaching the China borders with NK. Then in the
ensuing battles, China managed to push the US back to the 38 line
which is the border between NK and South Korea now. So the
net war result after China's intervention was that US retreated the
whole length of NK, from near the China-NK border back to the NK-SK
border. 
4)"Though when they did need to fight foreign enemies i believe
they lost most of their wars?" Obviously you have
not read much about history, especially China's history. If what
you said really happened, there wouldn't be a China today. It is
the only civilization that survived >5000 years.
Throughout its 5000 years of history, China had eliminated
numerous enemies that you don't hear of today because their nations
were already wiped out by China. You don't hear about
those Chinese heroic stories because much of the literature today
is influenced by recent Western culture (at least in this part of
the world). And I guess you also forgot about the Sino-Indian war
and the Sino-Vietnam war.
5)Yes, China became weak, but only during this recent 200 years
(out of 5000 years) of history. Even so, it still took an
alliance of 8 most powerful industrialized
countries at that time(USA, British, Germany, Russia,
Japan, France, Spain, Portugal(?)) to subdue China in the
"°Ë¹úÁ¬¾ü" war.
6)Other than that, China was only overrun 2 times 
during
its long history: first by the Mongols and later by the Manchus.
But now, both inner Mongolia and Manchou are part of China (not
vise versa).
