“I have to want it for a year”
That might be the best rule of thumb for making any kind of big or lasting decision.
Tattoos, of course, are permanent. So it’s better to know you really want one before you get one.
Same goes with buying a house or a horse or a car. They’re not permanent decisions, but they are large enough that it’ll hurt your bank balance if you choose to back out of them prematurely.
There’s little you could lose by waiting a year to discover if you really want (or need) something bad enough to get it.
On the other hand, getting something only to decide you don’t like it, want it, or need it is a burden best avoided.