Muscle Soreness (or lack thereof)

I'm about to give so much detail, but I need help/insight into this issue:

I work out five days a week, with the two rest days still consisting of a 1 mile easy walk, just to keep my legs a-going. I research fitness all the time, always trying to incorporate new workouts into my sessions so that my body does not get accustomed to a certain workout. About 3 of my workout days include cardio (running), 1 day is spent on a long run (around 5+ miles), and the last one is spent on leg day only. In addition to the cardio on those 3 workout days, I strength train using exercises that focus on using my body weight. Most recently, I began TRX training, which I love by the way! Here is my problem: I am never sore! My body feels stronger, I'm able to do so much more in the gym. I love every bit of the way my body is changing! I'm sure for most people, not being sore after a workout is a dream, but I don't see it that way.

I've read that muscles, normally should feel sore, not to be confused with pain, the day after a good workout, because your muscles are repairing muscle tears, but what does it mean if I NEVER get sore. The best way I can describe my muscles the day after a workout is the feeling of being stronger and capable, always ready for the next workout. I thought that maybe I'm not pushing myself hard enough, but tonight, I went as hard as I felt possible, while still being conscious of my body's limit, I even got my shortest mile time and my strength training was challenging, yet as I'm writing this, my body feels absolutely fine!

I'll include info about my diet, because that may be helpful. My biggest problem is not eating enough calories, but about four weeks ago, I began meal prepping to ensure that I get as many calories as I need. For protein, I eat grilled chicken, lean turkey, and fish. After my workout, I drink a protein shake within 30 minutes of my workout, if possible.

I know not being sore after intense workouts seems silly, but I'm aching for it. I've been trying to find one that does it, but I can't! I feel my body is reaping the benefits of the exercise, but I just want to understand why.