I have not done the exact math before responding, but to get a collision is far beyond the scale of getting hit by lightning multiple times. I think it would be more like getting struck by lightning every day for a year or a decade kind of thing.
Yep. It is very unlikely. There are awfully lots and lots of numbers in a private key.
But, anything can happen. And sometimes amazing things do happen.
There are different scales of unlikely. There is winning a lottery unlikely and falling through the floor due to quantum tunneling of every particle in your body unlikely. It is one thing to win a lottery twice and another to trow a can of toothpicks on the floor and them all stacking up vertically one on top of another and staying balanced like that.
You simply don't understand the scale here. Winning a lottery is more common then one in a billion and a billion is a joke for address collision. If there was a lottery that only one in 7 billion people won, getting address collision is like one person wining it billion times in a row all of a sudden (actually not even close, not even quadrillion is anywhere close, the number is so high that you can't possibly humanly understand).
Bitcoin private key is usually a 256-bit number, that is like 77 zeros. A billion is just 9. A billion of billions (quadrillion) is just 18. So try quadrillion sets of quadrillion sets of quadrillion sets of quadrillion numbers, well if you can wrap your head around it (you can't) it is still 100 000 that amount.