I think it's more rich and complex than seeing someone as 'perfect'.

There's splitting, like when a child has to see a parent as all good to preserve a sense of safety. This is perhaps where you you see them as perfect, where they can do no wrong and defend the person even when they did wrong. Similar to black and white thinking, this is where your mind can't integrate two opposing concepts and in that mindset, and often a person can alternate from idealizing to devaluing. This can change when your object relations changes.

There's also falling in love, where you might not necessarily see the T as perfect, but you may love their imperfections. This is where you may see them 'better ' then how they really are. Better in that when it fades, you may view them as more average and realistic.

Then there's feeling like a child, that for me coincided with the falling in love feelings. Depending on the age I felt, sometimes he seemed larger than life, and strong and powerful. When I looked at him, I felt excited to see him and felt a baby seeing her mother upon waking up in the morning in her crib. I remember feeling this vividly,
and saying to T, "you seem soo big and strong". It felt amazing at the time. Everything he did was so loveable, and sometimes he seemed like a giant teddy bear. At the same time, I felt weak and helpless, like an infant.

I didn't experience splitting which is more cognitive, but experienced the latter, which is transference and related to memories captured by parts. My parts integrated and we worked through the transference, so I only see him for who he is now. I still think he's cute and lovable, but it's more affectionate rather than from the mindset of a child. I no longer see him as strong and powerful.

The child idealization was interesting when it was occurring. Until a certain age, every child idealizes the parent who takes care of them. I just happened to experience what that felt like in therapy. I never thought he was perfect because my adult self was participating in the therapy as well and kept the rational perspective of everything.

I think it can be a mix of these things. Can you relate to any of that? From what you wrote here, I can't say either way if you idealized your T. If you have other posts that spell it out more, I could take a look.