I would have been too if I knew how good the stuff in it was

I think at that age (or any age really) they can get a little clingy - be it from a developmental stage - or if they feel they need more attention from mummy. I know from working as much as I did back then, it made him more boob crazy. It was also not long before my divorce, so I think they can sense things and seek security. Perhaps look at whats going on at home, any changes (moves, new people, new carers), stresses and if you've been busier than normal too. Maybe some more one on one time with distractions, looking at things, doing things.

I know at the height of that obsession for my son, I decided to cold wean him at 3. He was so upset by this that he no longer went to me when he was upset and cried for daddy. He was really upset with me and it broke my heart.

So look for things on the outside first, it may well improve things.