Since you asked, no it didn't take 6 years to reach E-5. I could have gone higher (I was offered to go to Officer Candidate School as a Warrant Officer if I stayed in), but I wanted out so I kicked it in a P-3 (submarine chaser) squadron my final two years, until my enlistment was up.
Yes, I spent 6 years in college (probably closer to 8 years if you add all of the classes I took while I was in the Navy). The reasons for that include that I was extremely active in student politics, so in order to do both things well (get grades and do a good job as a student leader), I cut back my unit load to 12 units (3 classes) the year that I was elected as Vice-President. I also took a semester off when my Mother unexpectedly passed away.
Additionally, I switched majors three times (Social Work, Sociology, and finally History), and also pursued a Minor in Psychology, and earned a secondary education teaching credential (High School).
I was able to afford college for so many years because of my GI Bill income, my student government stipend, and various grants and scholarships (my wife was also earning money with her job; we bought a house while I was still in college).
I started working at NCR Computers during my last two years of college, so I already had a good job and income before exiting college.
I had an excellent college experience, and don't regret it for a day.
Like I said:
ADG