What works with computers does also with humans. What a surprise: misbehaving.net: The power of a nod. No but seriously my experience was a bit similar. In highschool I took a ‘computer science’ class with a male teacher and all guys. Some of the guys were obviously the better hackers (writing 30k lines of assembler to display fractals in highschool qualifies I guess) but I am the only one who actually selected comp science for my future job. My teacher respected me and while he was a very strict teacher, he was also very good at teaching some of the basic concepts I would encounter again at university.
I knew before taking that class that I wanted to get my degree in computer science. I am sure I’d have done it anyway if the teacher had been a jerk. But maybe not and there may be a lot of people out there which quit if they get enough negative feedback or even too little positive feedback.
As I posted some days ago. Words stick. So if you get the chance to do some good by telling someone that you think their work is good: do so. You’ll make their day and maybe change their lives.