The first one is from inside. It is largely biological. Like you feel pain, tired, sleepy, etc. Those things make you crampy or upset. Or simply emotional due to fluctuation in hormone level as a result of some physical activities.
The second one is from outside. Namely, what happen outside that affect how we feel. That is usually because we have already established certain expectation as a result of years of experience of either observing others or in person of what leads to what among things.
For example, when we won a prize in lottery, we felt like we get something out of nothing. Virtually, no effort had been made other than just showing up in the right place or bought a cheap ticket. However, what we won had value. We could use it ourselves, or gave it to others which could generate some returns of favor. Therefore, having gain something ended up making us feel good, as it can generate great consequence that we will benefit one way or the other. Therefore, next time when we won a prize, we will feel good immediately, even though the consequence of using the prize has not yet begun.
As experiences are being accumulated everyday, unless we suffer from memory loss. It is very hard to change a person’s expectation in perceptions. The older we are, the harder to change. Somehow, this becomes a building block of our characters.
However, there are so few people will get a grip of the fact that just because XXX happens externally doesn’t mean that we must feel YYY. The relationship between XXX and YYY can be de-linked, especially, when YYY is something negative. Unlike mathematics, double negativity doesn’t generate positivity in human emotion. That’s why when I read that ‘We may not be able to change what happens around us, but we can choose to react”, I felt like a light bulb is flashing inside my head. It sounds so simply and logical, how come I’ve never thought of that?!....I’m sure it is not something new, it must be first cited thousand years ago by some wise philosophers. However, so few people that I know have ever mentioned that it is something we can do to make us feel better, which can lead to positive actions and consequence for us as well as others around us.