aaaah i love this question. it constantly amazes me how it's not just the first year or two that they have these...it's just that walking and talking are SO huge...it's really us parents who get to enjoy the others :)
my son is 5 1/2. he has always had a problem with swimming, he's just not a natural water baby. most summers he spends the first month or two at the pool clinging to me, SLLLLOOOOWWWWLLLLYYY getting accustomed to the water and trusting it. by the end of the summer he's always fine but it takes FOREVER. last august he broke his arm, so his summer was cut short...and i was dreading another few weeks of freaking out in the water this summer, possibly even worse because of his short summer last year.
NOPE! first time in a few weeks ago, and after about 5 minutes he was going nuts. he turned into a fish on me! i love it!!
and yesterday he emptied the dishwasher in SIX minutes :)
also, he discovered legos. i LOVE that. he plays with them for hours at a time - best toy ever! i'm so glad he's "big enough" to play with them now! (he never really got into the duplo blocks - talking REAL legos, here!)
OH and also, he now gets the mail himself (we do have to cross the street, so i am right there watching) and brings the dumpster up from the road on trash day.
he's getting so big :) last one i promise - this week he attempted to shave lol. cut his little upper lip too! that might not seem like one - but he has not always been close to dad - it took a long time for dad to come around and be the stellar father that he is now - and i really took it to heart, that he wanted to be "just like daddy", and was trying to shave. THAT is what a father/son relationship should be! it was kind of bittersweet (as i cleaned up blood...lol - just a little, and yes, the razors are now securely hidden! not so great mom moment there...lol)
i love the "non traditional" milestones. hubby and i still delight in them together, even though the rest of the world doesn't really care...lol. great question!