Charlie Sheen -- Just Got My HS Diploma... College Will Be 'HELLA FUN!'

Charlie Sheen ... GOES TO COLLEGE??

Now, that the Warlock has finally obtained his diploma from Santa Monica High School (30 years behind schedule) ... Charlie tells TMZ college would be "HELLA FUN."

The 48-year-old graduate just called "TMZ Live" to talk about his accomplishment -- and explained how he managed to finally complete HS, even though he only showed up for class 33% of the time.

Charlie also explains why he was so passionate about getting his diploma -- and what he plans to do next.

Check out the clip.