early introduction of solids

Most health organizations (AAP, UNICEF, WHO, etc.) recommend waiting until around 6 months to introduce anything other than breast milk or formula.

For moms who introduced earlier than 6 months, what was your reasoning? (Pediatrician said to, hoping baby would sleep longer, etc). Not trying to start an argument, just wondering.

Edit: if you did introduce solids early, did you know the recommendations before doing so?