What is happening behind the scenes is that your JSP is being turned into a Java file, compiled and loaded. This compilation only happens once, so after the first load, the file doesn't take long to load anymore.

JSP pages are translated into Java servlets behind the scenes. The JSP container converts the JSP into Java source code, compiles it into a servlet class, and loads it. This translation and compilation happens only once when the JSP is first requested, making subsequent loads much faster since only the compiled servlet needs to be executed.