Why are beginners not finding bugs

A lot of us will have good understanding of both client side and server side bugs but still we are not able to find bugs. For beginners and sometime experienced hackers think that it's may be because we lack knowledge about these vulnerbilities.

As a beginner i think my first mistake i note that i was learning a lot but hunting very rare mean that i was so interested in learning things that's feels productive but actually you are missing what real functionalities break in apps.

Second one that is still i know i am stuck is wrong program selection.I have selected the programs which have less functionalities to test.Mostly static or just very few assets.This is still one of the important reasons that i am stuck here and trying to out.

Maybe there are other reasons which making me and other stuck but i have figured out these in my methodology.