They start getting extensive if you do really weird stuff or you were born before computers automated alot of this stuff and made explicit calculus essentially unimportant.
You start getting a feel for where some of these formulas get strange if you take complex analysis and they start showing you some of the more bizarre integrals you can cheat out of.
@Scarlet It's more similar than different. Instead of multiplying stuff you're integrating stuff. But becaues integration is hard to do in general it works out to memorizing lots of derivatives (which are straightforward) and tricks.
Once upon a time, before you could simulate everything on a computer you'd have books of solved integrals for weird cases that were hard to just figure out on your own.
No one really does this stuff as much anymore. For most applied purposes you can do an approximate simulation on a computer and explicit solutions are less important than manipulations.
