Why would Gollum like climbing trees in fair weather?

Question

This question, asked yesterday, put a somewhat related question into my mind. As quoted in that question:

‘In the days of fair weather we led Gollum through the woods; and there was a high tree standing alone far from the others which he liked to climb. Often we let him mount up to the highest branches, until he felt the free wind; but we set a guard at the tree’s foot. One day he refused to come down, and the guards had no mind to climb after him: he had learned the trick of clinging to boughs with his feet as well as with his hands; so they sat by the tree far into the night.’

Now, it is quite well-established that Gollum’s long and gradual transformation and eventual retreat into the pits of Moria had entailed a deep and unwavering fear and hatred of the Moon and—especially—the Sun (even the stars he is suspicious of). Even in the parts of The Two Towers and Return of the King where his Gollum persona is less prominent and his long-forgotten Sméagol persona comes to the fore, he mistrusts the ‘Yellow Face’ and always prefers to lie in hiding during the day and on clear, moonlit nights; so this phobia of celestial bodies is not purely a Gollum thing that goes away when Gollum goes away.

And yet, if we are to trust Legolas, when he was held captive by the Elves in Mirkwood—a place quite sheltered from sunshine and one where he ought to be quite happy, apart from the presence of elves—he apparently enjoyed something so out of character as

• climbing a tree that stood alone, exposed, and unprotected,
• climbing up so high that he could feel “the free wind” (i.e., presumably so high that he was above the forest itself and exposed to the sky),
• doing all this “in the days of fair weather”, when the Sun must be assumed to be out.

How can this be?

Answer 1

Here is my non canon two cents worth of an opinion: Gollum did not pick the remote tree that he was allowed to climb. Knowing Gollum would immediately scamper away through the treetops, his captors would have chosen an isolated tree or none at all. I would think Gollum liked the exercise and the illusion of freedom, but I think he was resigned to climb that tree because it was the only tree he was allowed to climb in order to get the exercise and illusion of freedom.

Answer 2

Gollum had just been tortured at length by Sauron in a deep, dark pit under Mordor. I guess that for a while that changed his attitude to the open air and sunlight. He must have been severely traumatised by his recent experiences and thus acting out of character.