Hey guys,
I'm a 23 yr old male 6'1 195 pounds.
3 years ago I weighed 220+ pounds and decided to change all that by hitting the gym and hitting it hard. I did cardio, weightlifting, and my diet was very clean. As you can see I lost around 30 pounds.

While trying to lose weight I was pyrammiding sets 16-14-12-10 at heavy, but reasonable weights. Realizing I got down to a good weight I started trying to build more muscle.

Now my sets look like 10-8-6-4...I'm benching almost 300 pounds which is more than I ever could, and I'm doing huge amounts of weights compared to my friends and gym partners. For taking only protein and creatine, I will say I have made tremendous gains.

I am looking pretty good these days and I have built alot of muscle and receive compliments almost daily for my hard work. But My question is: Why am I more hungry now than ever? I eat healthy food but I eat constantly. I have to be around 4000 calories a day. I'm not putting on any fat because my waist size is still the same and my weight has only gone up a 2-3 pounds in 6 months. It seems obvious that my body is needing excess calories to repair the muscle fibers I am destroying in the gym. Is this healthy? Do you think this many calories a day is beneficial? Does it have to do with my age and the high amounts of weight I am lifting? Should I continue with this regimen? For some reason I keep thinking its gonna catch up with me and I'm gonna be fat out of nowhere.

Thanks for any info you can add.

The more muscle you have, the more calories you need to maintain it. That's exactly why people should srength train to lose fat. :)
It's perfectly healthy so long as you're not seeing any significant weight gain. You won't suddenly have 20 pounds hop on top of you as long as you're fairly regularly monitoring your weight, you should be fine. If you see it creeping up there, just cut back a little.
Btw, congrats on the progress. That's really impressive.