As i was turning thirty, I started to think: Am I useful? Yet not. Hence I would like to start this to share whatever i have learnt, what mistakes I did, wrong mindsets, etc.. So that maybe youngsters can have a better paths

For example: I did reject to learn Chinese when a lot of my friend were taking it, with a stupid thinking:
I do not need to learn enemy’s language!
Now what, I am trying to pick it up as beginner level with no friends/partners to study with. Knowing Chinese really brings your value up and gives you brighter career path. I have collected some of knowledge here for learning materials: