Law of nature is to change, so true it is. I always worry about concepts which I didn’t grasp easily and thing that bother me a lot is how will I understand them, learn them, if no one is there to help as all people around also don’t know much about it; Finally reached to conclusion that if we give two, one or even half hour daily to that particular topic even if we don’t understand much about it soon we will become expert in it. Your enemy will become your friend if you keep try for same.
New things are same for all, no one come in this world with full stack of knowledge, every person learn every thing on this earth only. The point is that the more time you will spend in a thing the more you will know about it, as you will have experience you get knowledge in it and become expert. So the topic/concept which was new and tough to you will be no more if you spend time on it.
Don’t take my words take your own example: you know very well how to add or multiply two numbers(correct?), how you learned them? May your teacher helped you initially to know the technique of performing addition/multiplication but ultimately you practice to learn it. And does that teacher is still with you to teach each and every new thing or do you have guaranty that, that teacher will remain with you forever? Absolutely not. You should be capable enough to find your own ways to get the things done.
In order to learn new concept/topic very first thing I do is use internet wisely, gather upper level knowledge of that topic through internet by reading various posts but as we can’t trust each and every information present of internet, one need to put more efforts to become expert and also you can’t be expert in any thing if you don’t do it yourself. So after gathering top level knowledge on that topic I search for any online course/MOOC and read good books to get well sequenced and trusted knowledge.
So the point is that things doesn’t change themselves with time, they change by doing things. Now doer could be you or other who will change it!