When you asked him, Bertie had trouble telling you what he most disliked about time travel.
Obviously, having to arrive in each new era stark naked was not the most pleasant experience. It usually meant having at least a few embarrassing moments (though it could occasionally have its upsides, such as the time he dimensionally slipped into that alternate reality where women had the same psychosexual visual response to nudity the way that men did in his reality . . .)
He was bothered that he could not change history, obviously.
He’d taken Causality 101 in college, and was fully conversant with the Heisenberg-Lurie equations relating to the Novikov self-consistency principle. Even so, he’d tested this idea by trying to kill Hitler. (Every first-year time traveler tries to kill Hitler at least a couple of times.) Yes, not being able to alter history was bad.
Then there was the HOSE.