Would a Patronus animal change throughout your life, if different things make you happy to what you used to like?
Only if it’s a very severe emotional change.
Patronuses can change, but it only tends to happen because of a drastic emotional change. Harry asks Lupin why someone’s Patronus would change, and Lupin tells him that they can change because of a great shock or emotional upheaval.
“Tonks’s Patronus has changed its form,’ he told him. ‘Snape said so, anyway. I didn’t know that could happen. Why would your Patronus change?’
Lupin took his time chewing his turkey and swallowing before saying slowly, ‘Sometimes … a great shock … an emotional upheaval …”
- Harry Potter and the Half-Blood Prince, Chapter 16 (A Very Frosty Christmas)
From what Lupin says, it presumably takes a sufficiently large emotional change to cause the Patronus to change. Therefore, it seems unlikely that small changes in what sort of thing makes someone happy would affect the Patronus form. Also, changing the memory used to conjure it won’t necessarily change its form. Additionally, this is also confirmed in the Pottermore writing by JKR on the Patronus Charm - it takes a profound shift in character.
The form of a Patronus may change during the course of a witch or wizard’s life. Instances have been known of the form of the Patronus transforming due to bereavement, falling in love or profound shifts in a person’s character.
- Patronus Charm (Pottermore)
Therefore, it wouldn’t change due to relatively minor changes in what makes someone happy.