Selling vs. Executing Call Options

I bought an option for the first time in my life back in February.

Of course, conventional wisdom from statistics is selling it before execution date.

But what is the “rule of thumb” in deciding? In other words, in what occasion is it more rational to exercise option?

For an example, the contract I bought is NVDA $300 (breakeven $305.45) 5/20/2022.
But my question is more general.