A lot of the power of the orgasm you're describing is due to what is sometimes referred to as "New Relationship Energy", or NRE. My wife experienced that after she was shared and found it to be almost intoxicating. In reality, there's no reason to allow yourself to feel inadequate because quite frankly, you're not "new", and without a time machine, you'll never be that again, possibly like you were when you first started seeing each other. Remember that "first kiss"? Well, you only get one of those. That's why a lot of marital sex is sooooooo satisfying. You get to feel a bit of NRE again.