coffee

Although I like the taste of coffee, I usually drink coffee at least once a month. 
If I will  drink too much coffee, I usually experience palpitations. 
Often times  after drinking coffee I can't sleep well which makes me feel uncomfortable.
My wife doesn't feel these symptoms and she can even sleep early after drinking coffee.
In spite of she doesn't like to drink too much coffee because we need to control our food expenses.
In fact drinking too much coffee is unhealthy.
In Taiwan some people are thinking that drinking coffee is a fashion trend, 
because whenever they have  a cup of coffee in their hands,it's  a kind of noble moves. 
In my opinion that's not a bad habit, if they will feel happy and will not try to interfere to other people's lives. Why not?