Part Time Senior Student - How To Enjoy This Free Time

Hi everyone, 

I had an existential crisis last night and woke up this morning questioning how I should approach this upcoming school year. 

I am a 22 year old student who is going to be enrolling in his 5th year as a part time student and as such, will have ample time on my hands. 

Notwithstanding recruiting preparation, career goals, and completing courses, I was wondering to those in their mid to late 20s who have looked back and thought what they could do now with what I consider "Free Time", what would you wish you would have done then to enjoy this youthful opportunity? 

I have always been ambitious and I am obviously not trying to get too distracted, but considering what you know now, how would you spend the remaining time on your hands to have an experience that you would not otherwise be able to do when you enter the work-force?