On a Dutch website I read that Java was first released on April May 23, 1995. That is exactly 20 years ago tomorrow. That was not yet version 1.0 - that came out on January 23, 1996. (I couldn't find any other website that mentioned the exact date of May 23, 1995 - many websites say "1995" but not the exact date).
My first experience with Java was in 1998. I had the book Java Unleashed, which has a star on the front that says "Covers Java 1.0!". Together with a colleague I learned Java in my free time. At work I was programming in C++ at that time. Our project was to write an applet to play chess. It displayed a chess board, on which you could drag and drop chess pieces and play against the computer.
It went quickly from there, a year later our company formed a new department for Java projects, and I switched from C++ to Java. I started working on J2EE projects. And I've been working with Java ever since.
I've heard March, April and May as the date. It's clearly this year though so happy 20th Java!
I started learning Java the summer between high school and college. I had already taken Intro to Pascal and C++ in high school and didn't want to take intro to programming a third time. So I took a "Java" test to place out of it. I didn't know much Java then and was grateful there were a number of questions where the answer was the same in C++ and Java.
Started working with Java in Aug '97. First paid assignment was to develop a GUI in AWT. Later in Swing. Learnt the hard way that AWT and Swing cannot be mixed:D Learnt the old style event handling but thankfully never had to develop code in it because event based event handling was released by the time I started coding!
Was also working on some COM/DCOM stuff but, again thankfully, switched to CORBA :D
Started playing with it in 1996, around the time I was also learning Smalltalk. It was interesting to compare different approaches to OO, and I liked the fact that Java had no pointers, but couldn't think of much to do with it at the time. Picked it up again around 2000, when EJB came on the scene.
I first started doing Java in early '97 after working in C++ since '92 (well, I'd been on the ANSI C++ Committee from early '92 and I'd gotten fed up of C++'s complexity and Java looked like a really refreshing change!). When Java "happened", I was the editor of a C++ journal called "Overload". You can read my initial thoughts on Java in the editorial (page 3) of http://accu.org/var/uploads/journals/overload16.pdf which came out in October '96 and again in http://accu.org/index.php/journals/1404 (January '97). I was very skeptical of this "new kid on the block" at first but began to warm quickly and by Overload 20 (June 97) was beginning to think Java had some benefits over C++ (see The Casting Vote, pages 7 & 8) in http://accu.org/var/uploads/journals/overload20.pdf
I stepped down from the C++ Committee in '99 by which time I was pretty much a full-time Java programmer. I stuck with Java until Java 5 appeared (September 2004) and that was the first release I thought was a bit of a mess. I moved on to other languages and watched Java 6 and Java 7 roll out with some disdain. By that time I'd been wooed by Groovy (2008/2009) and then Scala (2009/2010) and then fell in love with Clojure (2011-now). My first real love -- functional programming -- was mainstream and I had a language I could use for that. Java? Oh poor old Java was so old school and so far behind!