I behave differently in therapy than I do outside of therapy, so it's possible you're in the same boat as me and your therapist just isn't picking up on the behaviors.

Basically: My therapist is nice, but more of the serious type. I've tried cracking jokes with her and she laughs at them occasionally, but she'll usually just politely smile in acknowledgement or she'll keep a straight face, so I don't tell jokes anymore or try to be funny with her. I'll be in a funny mood, though, when I'm hypomanic or manic and crack lots of jokes with people--just not her. (I get irritated when people don't like my jokes because I genuinely believe I'm a rising star comedian.) I also consciously focus on sitting still when hypomanic/manic even though I can't sit still outside of therapy. It pains me to sit still and I'm going nuts, but I can barely manage it for the most part by crossing my ankles tightly and focusing REALLY hard. However, because I've suppressed that energy, I start pacing around endlessly when I get back from therapy. And at work I talk up a storm. She just never sees those symptoms. Hell, I've never even told her when I was depressed and I can hide it well.

My previous therapist, however.... He saw me manic and depressed a bunch of times. (I had bawled my eyes out in front of him a small handful of times, and a couple of times he had asked me, "Are you manic??? You said you haven't slept in 2.5 days and you seem energetic.") I was not controlled by meds whatsoever. I think if my current therapist saw me off meds (or on meds that don't control me), she'd see how bad I can get.