there are also some downsides like:
tired - I never realised how much I loved sleeping in, until I couldn't do it anymore
pain - being headbutted, kicked in the nuts and have trucks "driven" into your foot
repetition - hearing the person in the back of the car saying tme same word over and over and over and (repeat endlessly) does get to be rather grating.
these just counterpoint the upsides:
awe - how quickly they learn to do things, whether it is stacking blocks on top of one another or saying words.
smiles - nothing beats the "that is my daddy/mummy" smile from a toddler
plus all the others things people have already mentioned
