About to go on soapbox…I absolutely hate hearing people say that physical therapy is boring or not challenging. When in PT, you should absolutely be pushed smartly by a DOCTOR OF PHYSICAL THERAPY (that knows and respects tissue healing timeframes).
When you get stronger, it's because you put a supramaximal stimulus on your muscles (lifting more than it's used to), so the body responded and "built" more muscle and got more efficient and using them.
When you lose weight on a diet, it's because you entered into a negative caloric deficit (ate less than you are used to), so your body responded and lost weight.
When you crash after a two-day binger of partying and sleep for 18 hours in a row, it's because your body responded to the lack of sleep the previous nights and "caught up" on sleep.
The body is SMART and only responded to CHANGES from its status quo. So if you're going to PT and doing the SAME THING EVERY DAY FOR WEEKS ON END, chances are you're not benefiting as much as you can be because you're not adapting to any new stimuli. Now, that doesn't mean that there isn't a period of time where you are doing lower level activation exercises like after surgery, building the fundamentals to higher order movement patterns, or to rest injured tissues. But it absolutely means that your exercises should be periodically varied and changed, to provide a NEW STIMULUS to your body/brain.
And "constantly varied and changed" can be sometimes be as simple as changing the tempo! Or adding in a balance component (shown in video), or even putting two exercise you've already done together into one (shown in video).