Ledger Nano and BTC!

1M Ago
After owning a more than full BTC and everyone suggested me to keep the BTC on hardware wallet which I did eventually. Now bit concern about seed phase, why everyone saying not to store seed phase on iphone notes or drives? Iphone notes are very secure no one can break in your iPhones even if you lost it. I am thinking to store it on notes too just without 3/4 phase and I will memorise those. Your thoughts please ..