Either this fellow is dead or my watch has stopped...Groucho Marx

Walk down your street or through your local shopping centre and look for enthusiastic retailers.  You'll have to check your watch.  It's as though the majority of them have been hit by a time delay spray.
Ardour; Fanaticism; Ebullience; Devotion; Eagerness; Excitement; Verve; Willingness; Eccentricity; Help; Devotion; Co-operation; Intensity; Obsessiveness; Vitality.
Do you think that's a tad over the top?  Perhaps you're scared of having this effect on people.

(I was once giving a seminar to a group of local government employees.  As you can imagine, I was behaving as my normal low-key, genteel self. When they broke for coffee, I overheard one woman say to her colleague, "I need a pill. Ms Enthusiasm here gives me a headache.")

Perhaps this list appeals to you more.  It's from the list of antonyms to enthusiasm:
Calculation; Calmness; Caution
So far, not so bad, but read on:

Carelessness; Coldness; Contempt; Coolness; Dejection; Disaffection; Doubt; Dullness; Indifference.
See  There's no sitting on the fence.  It's like this:  Either you're enthusiastic or you're a waste of space.  Either you're a hot spring or you're a mud hole.  In Rotorua, New Zealand, they have both.  The hot springs they cap and harness.  Their thermal energy is used to generate electricity to share light and power with many people.  As for the mud holes, people avoid them because they stink and stick to your shoes.

So, are you a geyser or a mud hole?