思う vs. 思っている

In my last week’s diary, I wanted to express that the “old web” was more interesting to me.

So here’s the sentence

昔のウェブはもっと面白い思う。
昔のウェブはもっと面白い思っている。

思う is meant to be more for the moment.
思っている has a longer duration for the thought, or it has been a belief.

In my case, both make sense but with a slight nuance. If I wanted to say I always thought the old web is more interesting, then 思っている would be better than 思う.

A helpful analogy I found was that 思う is like “put on,” and 思っている is like “wear.”