Yeah, that’s at least a part of the advantages of random combinations. Obviously, random is difficult to achieve, if you use only software, but that’s a whole different point…
BUT: Random also works just with characters. “qJAMLxGaTS” is also random (I used a script to generate it), and secure. Of course, no one can remember such a combination, but if you use numbers and symbols it just gets even worse without a real advantage as I wrote in my article, just have a look at the graph. This is why it doesn’t make much sense to require numbers and symbols making everything way harder to remember.
“Bastian1” is truly not a very secure password as it’s derived from my name, but using something like “bamastth” is. I can easily remember this as I just mixed up the words “Bastian” and “Matthias”. As there are lots of words out there and the attacker can’t know how you mixed yours it’s pretty secure and easy to remember. (There are other dangers like “Social Engineering” but again, a different topic…)
To sum it up: using numbers and symbols won’t bring (much) more security to your password. E. g. GCHQ has some advices how to create passwords here https://www.theguardian.com/technology/2015/sep/11/gchq-password-advice (There’s a link to the original source, the article explains some concerns about password managers as well)