Though we went through this only two years ago (and twice over at that!), it's amazing how many things about the infant stage I forgot. I've been so wrapped up in each next developmental stage with the twins, resulting in me being up on all things toddler. After Nolan was born, though, everything came back real fast. Let's be clear: infants are awesome (aside from nighttime wakings and diaper blowouts), toddlers are awesome (aside from all that newfound independence and utter lack of fear), but the difference between the two - and in two short years- is HUGE. And having those toddlers and a newborn only heightens the contrast between the two.
Infant: Soft, snuggly, and the perfect size to be held.
Toddler: Like to be held. Except when they don't. Often too wiggly to actually hold onto.
Infant: Needs a diaper change upwards of ten times a day. Occasional leakage. Mostly still during changing, though don't underestimate the power of their kicks.
Toddler: 5-6ish diaper changes a day. Minimal leakage, but when it's bad, it's BAD. Diaper changes involve a high-speed chase, tackle, and hog-tie to be completed.
Infant: Mostly sleeps, interrupted by short bursts of energy known as "alert times".
Toddler: Mostly a whirlwind of energy interrupted by short periods of sleep known as "an utter relief to their parents".
Infant: Pretty much silent.
Toddler: Volume is always turned up to 11, whether from imitating every word and/or sound they hear or banging/throwing/pressing buttons on all of their toys. At once.
Infant: Usually has a reason for crying, be it hunger, sleepiness, or a dirty diaper.
Toddler: Reason for crying is often unintelligible or nonexistent.
Infant: Eats 10-12 times a day. Sometimes resulting in a mess when what looks like the entirety of their meal is spit back up.
Toddler: Would eat 10-12 times a day if I let them. Crumbs, sticky fingers, and a mess in a three-foot perimeter around the high chair is a fact of everyday life.
Infant: Smells like a delicious combination of milk, sweetness, and what can only be described as "baby". Unless you've caught them right after a bad bout of spit-up.
Toddler: Smells like a blend of feet, dirt, and the most recent meal they've eaten; aka "toddler funk". Unless you've caught them right after bath time.
Infant: Totally and completely dependent on others for all of their needs.
Toddler: Minimally self-sufficient. Could probably live for a few days off the crumbs they scavange from between couch cushions and found in their car seats.