I hate going to the inside and working my way out, trying to remember what I picked up along the way.

My first language was GFA-Basic on the Atari, and it also had sigils. You could see at a glance what kind of variables you were dealing with. Un-annotated identifiers always bothered me, be that C, python or even shell. That forces me to annotate the type in the identifier, such as int_foo or member_foo or func_foo. But what if int_foo by accident doesn't hold an integer, but a short? Well sometimes it blows, sometimes you get a warning. Unsure what is which? Open the header file, go figure. Try to remember everything, to avoid going to the inside and work your way out.

Sigils are the best invention after sliced bread (and beer¹).

¹) strictly speaking, beer is not an invention, but a creation: "on the 8^th day, God created beer, and hath never been seen any more thereafter".