Of course it’s a good idea to strike while the iron is hot. If striking iron is what you do and you find some hot iron you should strike before it gets cold. It’s far better to strike than to spend time and energy re-heating the iron later.
The same goes if a friend happens to heat some iron up for you: it’s worth making something out of it.
Be ready. Take the opportunities that come your way. But don’t make the mistake of thinking that the best way to make horseshoes is to wander around hoping you’ll run into some hot iron. Don’t keep turning up at your friend’s house with nothing but a hammer and a hopeful smile.
Better to start by getting to know the people who ride horses in your neighbourhood, then to equip yourself with anvil, hammer, iron and fuel.
Heat your own iron.
Then you’ll be able to strike it as often as you like, and at a time and place that works for you.