Each time I would buy a new sippy cup or trainer cup for my kids I would have flashbacks to my single and dating days, "Will this be 'The One' or just end up like all the others and be another disappointment?" I have spent a sickening amount on money on sippy cups and novelty cups over the past 4 years... And don't even get me started on the aggravation that has come with trying to disassemble and reassemble them. I'm pretty certain you need a rocket science degree to properly do so... Or at least a full night's rest, of which I have neither. On an impromptu shopping trip to our local health food store, I finally found "The One." Lifefactory! (Interesting sidenote: I also met my husband while randomly grocery shopping). I bought two of the pink 12 oz sizes with a cautiously optimistic attitude to it's potential success. When I tried them out on my girls (Ages 2 and 4) I was blown away with how instant of a success they were! My daughters both drank all 12 oz within a couple of hours and drank even more when I refilled them. No nagging, prodding or bribing needed! Back in our sippy cup days, I couldn't even get them to drink 6 oz in a day! Thinking this might be a fluke, I filled them up the next day and, again, was so pleased with how much water my girls drank. They now go with us everywhere we go: Ballet, the library, trips to Grammy's, etc. We have been completely converted (my husband and I are proud owners of the 22 oz sizes) and I can't wait to get our sippy cup castoffs to Goodwill! Thank-you for finally being "The One."