Still remember that feeling of first typing xeyes & and xlock & and inspecting the result on that 14" color CRT screen (I was beaming more than it, perhaps).
Then by winter term 1996 I owned a refurbished HP9000-715/75 running HP-UX 9.03 (also X11-based), pre-owned and via uni discount and still the price of a car at the time... the only undergrad on my corridor who had a workstation in the dorm room (its 21" CRT filling most of the 9 m² space that was not occupied by the bed). My next goal then was to get all the manual books (X11 and HP-UX) - still got 'em.
HAPPY 40th BIRTHDAY, X11! And thanks to the X11 authors for making it available for free - imagine, X11 supported mice with 16 buttons already back then!