i sterilised until my son started crawling (nearly 10yrs ago because that was the 'done' thing).
this time, i never sterilised at all - again, the hospital advised me of this as it helps build their immune system. which makes perfect sense imo, especially when they start solids and crawling.
my baby girl is now 8mo and i still boil then cool the water for her formula, simply because we are rural and are on tankwater (not scheme). but she drinks enough of the bathwater that i wonder why i even bother!