Sometimes to make a mistake could teach us something useful for the future... ;)
If you say "to fall often is useful" it could mean that falling several times is useful. It should be "often, falling is useful" as in "at times falling helps".
I find this so tricky how the English words "falling" and "to fall" are both translated to the infinitive!
Because often here means that "Often, falling is useful" and not "Falling often is useful". :)