This is an interesting question.
Oddly enough, I may be in the minority on this one, but when I'm not wearing diapers I don't tend to feel much of anything, I certainly don't feel incomplete or anxious. I tend to wear quite frequently during the week and typically I have plenty of time, when work and adult responsibilities are taken care of, to tape up and regress. The only time I'm not in a diaper is when I'm focussed on work or school and when that happens, I don't have time to even think about diapers and being a baby let alone feel something intensely as a result.
That being said, of course I prefer to be wearing a diaper and in baby mode when I get the chance because being diapered and in the baby headspace is a very pure, fulfilling experience for me. Being diapered and little keeps me well rested, stress-free and it often times gives me extra energy when it comes to tackling adult tasks again, but if the going gets rough and I can't wear for a while, so be it, I know my diapers, onesies, pacis, rattles and stuffies will be waiting for me when I have the time
I guess, over time I've just gotten really good at balancing adulthood and babyhood. When I can wear and regress, I have a blast, I feel contented. If I can't wear and regress, I might be a little upset depending on how much work I have and what my schedule looks like, but for the most part I'm not even fazed.
Just as sure as the sun rises, I'll always be diapered and in baby mode again