The thing that makes me feel like a bad parent

I can't figure out naps. Not my own - I've had those down for years - but Cyrus's. I want to be careful how loudly I complain about this because so far nighttime sleep has been managable and I don't want some cosmic force out there to show me just how bad it could be by taking away my blissfully easy evenings.

That being said, I spend the better part of my day trying to a) figure out if Cyrus is tired, b) find that "magic time" when he supposedly will go down without crying, and then when I miss it (which I do almost all the time), c) try to get him to go to sleep.

Some people may argue that if he's not sleeping during the day then he must not be tired. But the thing is, when he gets enough sleep, he is a nearly perfect baby. He rarely cries, he smiles happily, he is a joy to be around. However, when he doesn't get enough sleep he spends most of his day fussing and has very little happy time.

Cyrus at about 4 weeks...back when naps were easy!

The worst part is that everything keeps changing! Again, I don't want to complain too loudly, because I do realize just how much worse this could be, but he has had stretches of two weeks or so at a time where naps are almost seemless. That's how I know what he can be like. But a little switch goes off every two weeks or so and I find myself in a day like today. He refused to nap for more than 45 minutes at a time, and all but once woke up screaming. When I nursed and rocked him into an almost sleep state and then put him in his crib, he began screaming again, as if he knew what was coming and just wasn't having any of it. But because I know he needs sleep, and he won't sleep in my arms anymore, I have to leave him in his crib to cry. (This is the part where I feel like a terrible parent). He eventually falls asleep after fussing, crying and cooing off and on for 20 minutes or so, only to wake up 40 minutes later, whereby I watch the clock and him, trying again to pinpoint that supposed magic time, and then start the whole process all over again!

Part of my problem is that I am just so darned concerned about doing it right. And although I logically know that it is unlikely, I keep fearing that I will mess him up forever. Now if the cycle repeats itself, he should be back to napping well again in a week or so...but what if that doesn't happen? I realize that I am exposing my naivety as a parent, but I keep worrying that this current state will last forever and that I'll go bonkers.

And yet what I keep coming back to is why will he go to sleep so easily at night (universe, please don't shoot me down for this), but refuse to take naps? And, why will he take naps for a while and then stop? Does anyone have any answers for this? I welcome any and all suggestions!