So ever since I can remember, I have always had a lower level of excitement towards things than other people. However, when I would get really excited I never knew how to express it (I still don't). Instead I just feel it building up inside me making me feel closed in, jittery, in a word, wanting to explode in every way possible. As a child I would do this by rappidly kicking my legs or other such explosive movements.
In addition to this, when I try and force myself to appear really excited(even if I am) it leaves me feeling very emotionally drained.
In other words, I have somewhat of an inability to express my emotions, which is why they build up inside me. I feel comfortable talking about my emotions, or writing about them, but have a hard time physically expressing them.

Any idea why this is?