Time will Tell

I'm hemming & hawing as to whether I should run the mothers day 5k this year. I stopped running in Oct of last year, mostly due to the weather. I think I ran 20 min (the max time allowed) on the treadmill at the gym ONCE.
So last week, when the weather wa gorgeous. I went for my first outdoor run this year. I was able to run 5K in 33 min, which proved to me that all my 'cross-training' of aerobics, elliptical & walking the dog have paid off.
I also looked back and last May I weighed 186 lb!! So, in theory since I weigh ~25 lb less, it should be easier to run, right?
Do you see the pattern here? I'm trying to convince myself- that running is good, it'll be easier & I should do it. Time will tell.
On a side note- congrats to mizfit on her completion of the Disney Half Marathon-WTG!!