Back when I was unwoke I was head over heels about my crushes. I idolised them, asked them for advice to learn from them and as a part of flirting, and believed all the advice they gave me. I regret doing this very, very much. Of course the crushes were unrequited and I ended up embarrassing myself but it was way more than that. I'm not going into the details but I ended up making some bad decisions that I regret very much. Some of my friends advised me to stop idolising my crushes and believing all of their advice without thinking things through, but I didn't discover this until it was too late.

Now that I am older, I realise it is very common for people to give advice half-heartedly. They'll just answer you with whatever came to their minds first instead of thinking about what you've asked in depth. If the guy you like is someone who doesn't like you back, then yes, there is the chance that he didn't give much thought to what you asked as he just doesn't care that much about you. Even if he is your SO, he may still not give much thought to what you're asking. Some men may also give bad advice on purpose to their SOs to ruin their careers or whatsoever.

Even if that guy put some thought into giving you good advice, he may still be biased. A lot of people do this based on their own experience without being aware of it. What the guy liked may not be something you will like and it's the same the other way around. It's hence a bad idea to put the guy you like on a pedestal and 100% follow through with his advice without analysing what he said. You are a unique human being and there's no reason why you should fully imitate someone.

And yes, being head over heels about a guy means you are vulnerable to believing everything he says without thinking things through yourself. Your brain will romanticise everything about him and overlook the fact that he gave you bad advice. Not only does a guy need to be vetted but his suggestions should be viewed in the same way.