siesta anyone?

can someone please explain to me how i can feel more tired when i am home with my little tot all day (or weekend or whatever) than at a normal day at work? i find it truly baffling. 

i admit, i live for the full days i am with her, but find myself needing a nap at her naptime (when i am supposed to be racing against the clock getting everything else done right?!) or daydreaming of coffee or planning what coffeeshop we attend pre or post naptime.

i also admit, i have a little mom guilt about this. should redirecting and playing with a toddler make me this tired? is it because i only have one to focus my attention and i refuse to have the TV play 'babysitter' ?? 

OR perhaps this mobile, curious little person is just tiring for that reason. i don't mean to use the word tiring in an negative way either. i love that my gal is mobile, curious, and adventuresome, but i think it's these things that wear me out. i work out of the house 4 days a week and there are plenty of days i hit that "wall" in the afternoon, but not enough to curl up and siesta. (although maybe being at home is more enticing as i listen to a sound machine on the monitor, open windows by beds and couches calling my name, snuggly blankets... that could be it).

i think bird is at an amazing age, but also a challenging one. every day she learns something new and i don't feel it's an exaggeration! little sponge- it's exciting.

i watched my two nieces with bird on friday and my friend asked who was the hardest. while no one child stood out as difficult, they are all well behaved, i'd still have to say lil birdie would win that title haha. jojo is 3, pottytrained, understands commands and can help when needed. dal is 9months- she is mobile, but a lot slower as she crawls and likes to be around the other kids. bird is quick and doesn't always get commands. redirection often seems like a broken record. they actually, for the most part, all play together nicely, but i have to say the 17m old, sneakily taking bites of her crayons and trying to stand on the table was the toughest.

see, i think we are at this middle stage right now; it was easy to sleep while baby sleeps when it's just one (and they sleep A LOT)... and as they get older there are more activities to introduce for their cognition and dexterity. i'm eager to start some new activities with her, but not sure what is appropriate for this age. we are set on sending her to montessori school in two or so years. does anyone have any montessori advice for this age? (i'm looking at you, littleonelove haha!) while it's not an option for me to stay home with her more than 1 day, i want to integrate more learning activities and exploration with her caregivers that don't involve exploring things like the wine rack or old ant traps.