<human>: I've been trying for 4 or 5 years to get motivated and keep going to the gym. I've have three week stints two or three times where I ran most days and was able to do 20-25 minute 3-mile runs. 

Currently, I'm not in bad shape - I'm 23, 5'9", and between 165 and 175 lbs depending on the week. Could probably run for 20 min on speed 7 or 8 mph right now if I wanted to, but I'd definitely feel it the next day.

Also, I smoke occasionally, and I know that's not good. That's mostly the reason I feel like I should work out or at least run regularly. I've tried vapes, and I think when the time is right, I'll switch back over and hopefully quit, or at least keep it more occasional..

I give myself good nutrition by drinking a great green vege health drink a lot, but also eat mostly crap otherwise, (ramen, cheeseburgers, subs, etc). 

So to summarize, I eat decently, I'm not fat, I'm in decent shape, but don't have the healthiest lifestyle. That's my motivation to go to the gym, but honestly, that just isn't enough, and haven't found anything yet to keep me going.

I do well on a schedule and have tried going with buddies, but I usually back out or am too busy. I know I need to make a regular time in my schedule to get it done, but I have trouble seeing the point of going through the trouble and using up time I could be doing things, (or nothing). 

This is especially true because there's no reason I know of that I actually need to be in better shape. 

How can I get myself motivated, when I really don't care, and by normal standards, I'm pretty healthy?

Could you distill the essence of the text into 1-3 sentences?
<bot>: Details above relevant, but I'm in a shape I'm pretty happy with, but don't know how to get motivated to get in better shape or if I even need to.