Me too, but the VBA object model is HUGE if you factor in Office apps and VBA by itself. Plenty of melon-mushing concepts you could learn. That is also the reason I try to help out at Mr. Excel on the vba side of things; wanting to learn and keep the old noodle supple. However, it is keeping me from doing other things, and lately I've been thinking I ought to drop all of it for at least a while. But it's like a drug!
If you want a challenge, learn a new language; one that isn't all that different from VB6 in some aspects and would provide a foundation - and a RAD development environment.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.