Part of normal learning cycle... I have lost count how many times i have goofed up something in electronics. Incorrectly set instruments, wrong settings, just plain reading it wrong, to putting regulator and other components wrong way in. Not to mention mistakes i have done on coding something: Various assembly languages, C, PHP, Perl...
Once spend day looking bug in firmware i had done. I had forgotten one single command from all that code...
Sometimes in afterwords just wondering, why the heck i didint notice that as its happening...