Difference between prepositions ‘for’ and ‘to’

Question

For ‘for’, in dictionaries there are two examples:

1. The box is too heavy for me to carry.
2. For her, books were as necessary to life as bread…

But I saw this in a video (4:30 here — mostly in Chinese) that if your friend ask you how his new tee looks like, you should say ‘to me, this tee looks nice’ instead of ‘for me, …’, because if you say the latter, the ‘for’ here would be understood as the ‘for’ in ‘if the tee is for me’. But why can’t this ‘for’ stay the same as in the examples above, especially as the second one, in the sense of expressing opinions from one’s own perspective?

Answer 1

In this context, "to me" means "in my opinion", so it's a good way to answer when someone asks for an opinion.

In this context, "for me" means "in my life/according to my beliefs/etc." so doesn't make sense as an answer to an opinion about a t-shirt.

In the context of a more personal question, like What is 'family'?, "for me..." is appropriate because "family" can mean different things do different people, and there's no wrong or right answers, just personal perspectives. For some, family is love and support, while for others it represents trauma and abuse. Neither person is right or wrong, so "for me" is a good way to answer.