Is it abnormal not really to be real fluent with these?
Don’t get me wrong I see the examples and as I went through lessons later on I see some of the examples come up that can be useful.
I am good with ones like:
^$ which can be useful for applying to everything (you use this one when dealing with Transit issues when multi-homing and need to filter) or ^63100$ apply to an AS specifically.
I also get and like the ones like 
which would give every AS that goes through AS 51 those are cool. (I had to take a picture and upload because could not figure out how to use the underscores in posting on the forums is there a trick to that?)
Even the more complex examples I could use but I am not getting this like I can start coding with it or something I am understanding it on the level that I can login to this site to get something I need or perhaps google it and search for something I need (minus the simple ones that I used at beginning those stuck) is that ok? or do I really need to drill on these or just understand what they are used for in searches and filters and know that I can look these up when I need?
Also do these Regular Expressions just deal with BGP AS?
I have touched upon these in Microsoft PowerShell as well though they applied to everything but was used for similar purpose of searches or filters and such.