While I can type faster than I can write, if I observe something that I want to record for later consideration, it's a lot quicker for me to whip out my notebook and a pen, than to whip out my computer, log in, launch a text editor then save my document.
I always have a notebook. I carry a small one in my back-left pocket, and take care always to have a pen.
I have a regular-sized notebook that I carry in my computer bag, that has graph paper rather than just lines for text, however as you say I don't have it with me.
With scientific notebooks, what's important is not to be neat, but to write it down so it's not forgotten.
At one time, for inventors, it was crucial to record the date upon which one invented something, however the US patent law was revised a few years ago so that we have "first to file" rather than "first to invent".
I even do stuff like take notes during TV commercials, if I see a product advertised that I might like to buy.
Perhaps I'm an aberration here but I've never seen a commercial and thought "oh, I'll buy that". I've often seen them and thought "that's cool" or even "I wonder how that works". It's clearly a conscious decision to consider buying things simply because they bought an ad slot in a show you watch, I find that quite strange.
[Senior Soft. Eng. in USA, guess you can afford anything that takes your fancy.]
Is it a common thing to do that with adverts?
On a side note you should still be recording when you "invented" something. If you were using it prior to the priority date of a patent application then you can't be prevented from continuing to use it; prior use is an absolute defence in patent infringement proceedings [ordinarily in patent law, you'd want to check this one in USC]. If you publicised it, even within a narrow definition of "public" then it can obviate the patent too; using a patent in public is sometimes enough for it to be considered citable against teh novelty of the later application.
There are lots of ads for things I really do find useful. Consider the controversial superbowl ad for the machine that makes homemade carbonated soda. Sodastream? It's controversial because it's manufactured in an Israeli settlement in the West Bank, however the factory employs many Palestinians.
I like to drink soda, so that's something I would conceivably buy based on the ad.
It wasn't just brand advertising, nor image advertising, but actually demonstrated how one actually uses the machine.
I transcribe to Evernote (or other note taking apps) as necessary, but this introduces a welcome step of filtering the raw output of transcribing.
YMMV.
Now you can do all these things on a computer, but you will either need to switch between several different apps, or have one very large, complex and likely costly app.
Not to be overall pedantic, but hand written lab notebooks are being replaced by electronic versions. That changed (in private labs) started back in the early 2000's.
In fact, if electronic notebooks are available, scientists are usually encouraged to not write anything down by hand as it might interfere with IP claims.
Sure, but certainly not in cursive.