no way! When I drank my first cup of Japanese green tea I didn't even know what l-theanine was. Since I felt very euphoric and relaxed after said cup I had to google the components of sencha to find out what caused this very pleasant sensation. However, the intensity of the effect does vary from day to day for me.
People are different.
interesting anecdotal response to the well cited research
These comments represent many anecdotal opinions. That's the value of comments around this article.
Science has proven this can have an affect. But even the study doesn't conclude this is 100% for everyone.