I was told to stick with professional sharpening; no whetstone for me

A little while ago I went in to get my knife sharpened professionally and in striking up a conversation, I asked their opinion on whetstones and if they had to pick two grits for a beginner, what might they suggest for my knife.

I mostly got a laugh rather than actual answer. Essentially, they said the learning curve without constant practice would take years and I'm better off just getting it done instead.

Is that a fair assessment? I'm admittedly a casual user, I don't have a range of knives, but I thought a stone would be nice to have on hand. Can anyone share their experience as a newbie and learning to use a stone independently (that is without instruction beyond the internet)?