Forgot pattern. No unlock by Google account option?

[Hadisultan]

Today someone pranked me by changing my lockscreen pattern. I didn't realise it was changed until I got back home. At first I thought I would get a 'forgot pattern' option after a few unsuccessful tries, however, to my dismay, it just kept locking my phone for 30 seconds after every 5 tries but I never got the forgot pattern option. The last time this happened was a year ago, when the phone was on Kitkat (now on 5.1 Lollipop), I got the forgot pattern option and then went on to unlock with my Google account, however this time it didn't happen. After a long time trying to hit and try random shapes, I got the pattern which was an L shape. However, I would like to know why the forgot pattern didn't show in case this happens again, I might not be so lucky. Can it be enabled through the settings?
When I was trying to figure out the pattern, I did some research and found out that Myxperia could be used to unlock the phone, however, due to over the top data charges I keep my mobile data off, as I can't afford even running the data for background applications. The WiFi in my building keeps changing and I have enter a new password regularly. So there are times where my phone isn't connected to the Internet unless I manually enter the WiFi password. Due to this I can't use Myxperia either.
So in my case, if I really did forget my pattern, couldn't use Myxperia, wasn't connected to the Internet on my phone and the forgot pattern option didn't show therefore I couldn't unlock with my Google account, what would I do? Would my phone become useless?

[John-BR]

Hi Hadisultan

Welcome to the Community.

If you are able to connect the phone to the internet you also have the option of the Android Device Manager to remotely unlock the phone. Otherwise you will want to run a procedure called a software repair that will wipe the handset.

Here's how to run the repair on PC Companion:

1. Install and open PC Companion then select Support Zone.
2. Phone Software Update.
3. Start.
4. Repair Phone
5. Continue
6. Accept data removal
7. Next
8. Wait for prepare
9. Select Phone
10. Follow the connection steps

And Bridge for Mac:

1. Launch Bridge for MAC without the handset connected.
2. On the Main Window select "Xperia > Repair Xperia Device".
3. Ensure the phone is charged and select "Ok" in the following window.
4. Select Continue on the following page.
5. Wait until the initialising step is finished the continue as below.

6 . Select your model of phone from the list that appears

7. Follow the connection steps that appear, ensuring that you are holding the relevant button down before during and after the connection phase until the update/repair begins.

[Hadisultan]

Even if I had Internet and was able to unlock my device, wouldn't I need the previous pattern to change to a new one. Something which the 'forgot pattern' didn't need. And the only method of unlocking being a full wipe is a big inconvenience. Is there no other alternative? And why did Sony get rid of the forgot pattern option anyway? All the other (non Sony android) phones that my friends/family use have these option.