Fingering

So, before today my boyfriend has been rubbing my clit and such through my pants and straight on. It feels good, no doubt about that, but I’ve never came from it. Today, however, he started fingering me and I started moaning (which I never do usually) and he says I was more tense. I find this odd because the only way I can ever get myself to orgasm is via my clit. I’m just wondering if it’s because it doesn’t take as much skill to finger as it would to work the clit...? Anyone else have similar experiences or just knows what’s up with that?