Why a vet says it in the first place
Plenty of symptoms genuinely do resolve on their own, and treating every one aggressively would mean unnecessary tests, medication, or stress for a pet who was going to be fine regardless. "Wait and see" is often the medically appropriate answer, not an easy way out of one.
What it actually asks of you
It's shorthand for "watch for it to change, not just for it to disappear." That means noticing if a symptom gets worse, spreads, or is joined by something new, not simply checking in a week later to see if it's still there.
Why this often goes wrong at home
Without a record, "waiting and seeing" tends to become genuinely just waiting, since a slow change is hard to notice day to day. By the follow-up appointment, the honest answer to "has anything changed?" is often a guess rather than an actual observation.
How to actually do the "seeing" part
A quick daily note covers it, nothing elaborate. Halo's daily log exists for exactly this, so "wait and see" turns into an actual timeline instead of a memory of a vague instruction from a few weeks ago.