Uncle- What do you do?

Me- I'm a software engineer

Uncle- My brother's friend's son is also a software engineer.

Me- (so what am I supposed to do about it?) yes that's nice

Uncle- I have a great idea, u should implement, I'm just telling you, it is a revolutionary idea

Me- (oh fuck, not again) yes tell

Uncle- you should make a matrimonial site which tracks what people do on internet and tell their to-be-spouses about it

Me - (yeah, I'll get sued for breach of privacy, and it has got nothing to do with my current line of work, and will probably cause divorces before marriage) yes great idea uncle

Uncle- see I told you this billion dollar idea, u should do hard work and make it

Just WHY in god's name do all uncles think laptop is a magic box in which I just have to type their idea in and it will spit out a website/software in 2 minutes. I don't go around advising them about their line of work.